Anti-KIR3D antibodies

ABSTRACT

The present invention provides antigen-binding proteins capable of binding to KIR3D polypeptides. The antibodies have increased activity in the treatment of disorders characterized by KIR3DL2-expressing cells, particularly CD4+ T cells, including malignancies such as Mycosis Fungoides and Sézary Syndrome.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Ser. No. 13/145,224, filed Nov.22, 2011, now U.S. Pat. No. 9,181,341, which is the U.S. national stageapplication of International Patent Application No. PCT/EP2010/050480,filed Jan. 15, 2010, which claims the benefit of U.S. Provisional PatentApplication No. 61/145,635, filed Jan. 19, 2009, the disclosures ofwhich are hereby incorporated by reference in their entireties,including all figures, tables and amino acid or nucleic acid sequences.

The Sequence Listing for this application is labeled “Seq-List.txt”which was created on Jun. 30, 2011 and is 37 KB. The entire contents ofthe sequence listing is incorporated herein by reference in itsentirety.

FIELD OF THE INVENTION

The present invention provides antigen-binding proteins capable ofbinding to KIR3DL2 polypeptides. The antibodies have increased activityin the treatment of disorders characterized by KIR3DL-expressing cells,particularly CD4+ T cells, including malignancies such as MycosisFungoides and Sézary Syndrome.

BACKGROUND

Killer immunoglobulin-like receptors (KIR) are a family of receptorsthat, along with C-type lectin receptors (CD94-NKG2), are used by humanNK cells and T-lymphocyte subsets to specifically recognize MHC class Imolecules. Certain inhibitory and activating KIR have highly similarextracellular domains and are recognised by the same monoclonalantibody, e.g. KIR2DL1 and KIR2DS1 are both recognised by EB6, and 2DL2and 2DS2 by GL183. Three criteria (number of extracellular Ig-likedomains (domains D0, D1, D2), cytoplasmic tail length, and sequenceanalogy) have been used to categorise the KIR proteins into 13 groups,namely KIR3DL1-2, KIR3DS1, KIR2DL1-5, and KIR2DS1-5. The nomenclature 2Dfor 2 domains or 3D for 3 domains gives the number of Ig-like domains;receptors with either long or short cytoplasmic domains are furtherclassified as L or S. (Pascal V. et al., 2007 J. Immunol. 179:1625-1633)The inhibitory receptors possess long (L) cytoplasmic tails (i.e.,KIR2DL or KIR3DL) containing a canonical ITIM that becomes tyrosinephosphorylated upon KIR engagement of their HLA class I ligands. Thephosphorylated ITIM recruits the Src homology 2 domain containingprotein tyrosine phosphatases Src homology 2 domain-containingphosphatase 1 and/or Src homology 2 domain-containing phosphatase 2,which dephosphorylate cellular substrates, thus aborting the NKactivation signal, i.e., sparing target cells with appropriate self-MHCclass I expression. Receptors with short (S) cytoplasmic tails lackITIMs (i.e., KIR2DS or KIR3DS). These activating KIR contain a chargedresidue within their transmembrane domain facilitating interaction withthe signaling chain KARAP/DAP12. Engagement of the KIR2DS family ofreceptors has been shown to lead to a cascade of KARAP/DAP12-mediatedsignaling events culminating in increased NK cell cytolytic activity andthe production of proinflammatory cytokines such as IFN-γ (Pascal et al.2007 J. Immunol. 179: 1625-1633). Mature NK cells are predicted toacquire at least one inhibitory receptor specific for a self-MHC class Imolecule, which generally functionally prevails over potentiallyauto-reactive activating molecules. It is proposed that the response ofNK cells represents the integrated outcome of both activating andinhibitory signalling by KIR and other receptors.

X-ray crystallographic analysis has provided high-resolution images ofKIR2DL2 bound to HLA-Cw3 and of KIR2DL1 bound to HLA-Cw4 (Boyington, etal. (2000) Nature. 405:537-543). In both complexes loops from theIg-like domains D1 and D2 of KIR2D are involved in binding to HLAmolecules. In comparison to the interactions of KIR2D with HLA-C, littleis known of the interaction between KIR3D and their ligands HLA-B orHLA-A. The KIR2D genes encoding HLA-C receptors form part of a largergroup of KIR called lineage III KIR and all KIR2D genes of lineage IIIcontain a pseudoexon encoding a D0 domain that is not incorporated intomature RNA. KIR2D genes are thus believed to have evolved from KIR3Dgenes. Human KIR specific for HLA-A and B form part of KIR lineage IIwhich is comprised solely of KIR3D which all comprise a D0 domain. TheD0 domain is the most N-terminal Ig-like domain in KIR3D proteins. Whilesome reports suggest that the D0 domain is not involved inligand-induced signalling (e.g., Snyder et al. (1999) Proc. Natl. Acad.Sci. USA. 96:3864-3869), others have proposed models where the D0 domaindoes not participate in ligand binding it may have an enhancing role insignaling. Khakoo et al. (2002, J. Exp. Med. 196(7):911-921) reportedthat various point mutations in the D1 and D2 domains of KIR3DL1, butnone of 15 different point mutations in D0, abrogated KIR3DL1 binding toBw4⁺ HLA-B.

It has been reported that several malignancies, autoimmune orinflammatory disorders involve CD4+ T cells that express KIR3Dreceptors. However, the functional role of KIR in T cells is largelyunknown, and KIR-mediated signalling has been reported only in CD8+T andNK cells, in which case KIR have been involved in regulating effectorcell cytotoxicity. The little knowledge of KIR signalling in CD4+ Tcells has been limited to activatory KIR (e.g. KIRDS polypeptides), andthese have been reported only to have a co-activatory role, rather thanthe true activatory role in NK cells (see e.g. Namekawa 2000, supra).The lack of true activatory function for KIRDS was reported to be due tomissing “DAP12” signalling adaptors in T cells (Snyder et al. (2003) J.Exp. Med. 197(4):437-49).

The existence of numerous anti-KIR antibodies has been reported in thescientific literature. Shin et al. (1999) Hybridoma 18(6): 521-527 forexample report a study of KIR antibodies. The majority of the antibodiesthat bound the KIR did not appear to inhibit the signal transductionmediated by the KIR and were therefore non-functional. Watzl C. et al.(2000) Tissue Antigens; 56: 240-247, identified “Lig1” antibodies thatbind a common epitope on KIR2D receptors (except for KIR2DL4) but didnot bind any KIR3D polypeptides. However, the Watzl et al. antibodieswere not functional in their ability to block KIR-ligand mediatedinhibition of NK cell cytotoxicity, nor did they inhibit binding ofKIR-Ig fusion proteins to MHC class I-expressing cells. Otherpublications cite the existence of antibodies reactive against variousKIR3D polypeptides. None of these antibodies are reported to distinguishKIR3D polypeptides from KIR2D polypeptides by binding all KIR3D (i.e.KIR3DL1, KIR3DL2 and KIR3DS1) yet no KIR2D polypeptides. Twoanti-KIR3DL2 antibodies have been reported: Q241 and Q66 (Pende, et al.(1996) J Exp Med 184:505-518). These two antibodies are of the IgMisotype and will be expected to have low ADCC activity, or if theirvariable regions were placed in the context of a bivalent IgG typeantibody, their affinity would generally decrease to the extent thatsignificant ADCC induction would be precluded. The existence of afurther KIR3DL2 antibody referred to only by the name of the “AZ158”cells producing it was reported (Parolini, S., et al. (2002) inLeucocyte Typing VII. D. Mason, editor. Oxford University Press, Oxford.415-417). Several antibodies have been reported to bind the monomericKIR3DL1 but not dimeric p140-KIR3DL2 (e.g. clone Z27 from the A. Morenagroup and DX9 from the L. Lanier group, both available from BectonDickinson). While KIR3DL1 and KIR3DS1 share high sequence identity(KIR3DS1 is an activating form of the KIRDL1 gene), KIR3DL2 and KIR3DL1differ in that KIR3DL2 are dimeric and share lower amino acid identitywith KIR3DL1, including within the ECD (86% identity). KIR3DL1 recognizethe MHC class I molecules HLA-B while KIR3DL2 recognize HLA-A.

Despite a great deal of research into the KIR family, and despite theexistence of research reagents binding to various KIR, the role ofcertain KIR such as KIR3D polypeptides remained to be elucidated. Theretherefore remained a need for improving anti-KIR based therapies.

SUMMARY OF THE INVENTION

The present invention results, inter alia, from the discovery ofantibodies that bind the D0 domain of KIR3D polypeptides. The D0 domainis located at amino acid residues 22 to 145, with reference to theKIR3DL2 polypeptide of SEQ ID NO 4. It was furthermore observed that theantibody having such functionality bound not only KIR3DL2, but alsoKIR3DL1 and KIR3DS1, and that the antibody bound a common determinant indomain D0 of these KIR3D proteins. The invention further results fromthe discovery that antibodies that bind KIR3DL2 polypeptides, and inparticular the D0 domain of KIR3D polypeptides, are able to directlyslow the proliferation of KIR3DL2-expressing CD4+ T cells, i.e. byinducing a KIR3DL2-mediated inhibitory signal. Previously only the D1and D2 domains have been reported to be essential in signaling inducedby binding of HLA molecule ligands to KIR3DL polypeptides. Additionally,it is shown that it is possible to obtain antibodies that are selectivefor the D0 domain over the D1 and D2 Ig-like domains, providing a meansto specifically target, identify and modulate the activity of the D0domain of KIR3D polypeptides. It was furthermore discovered that theanti-KIR3D antibodies having Fc portions that bind Fc receptors werecapable of mediating NK cell mediated ADCC toward KIR3DL2-expressingcells, independently of or in addition to any KIR3DL2-signalling effect.It was also observed that the antibodies' ability to mediate ADCC towardKIR3DL2-expressing cells could be significantly improved by modificationof the Fc portion of the antibody by producing it in a cell line whichgenerates hypofucosylated antibodies.

The present invention further provides antigen-binding compounds, e.g.antibodies, that bind a common determinant or epitope shared by theKIR3DL2 in dimeric or monomeric form, as well as the monomeric KIR3DL1and KIR3DS1. The antigen-binding compounds thereby provide a means todistinguish the KIR3D polypeptides from the KIR2D polypeptides. As shownin the Examples herein, an antibody that binds all KIR3D but not KIR2Dpolypeptides recognized slightly more than about half of NK cells froman individual donor. An antibody that recognizes all KIR (or at leastKIR2DL1 and KIR2DL2/3) on the other hand will bind each NK cell, asobserved in polyclonal NK populations from different donors (Watzl etal. 2000, supra), since every NK cell in every donor is believed toexpress a KIR2D receptor. Additionally, expression of KIR3D receptors onNK cells, particularly KIR3DS1, is believed to be at a relatively lowlevel, which may, without wishing to be bound by theory, have precludedsignificant ADCC-mediated depletion of NK cells by an IgG1 antibody. Asa result, the KIR3D-specific antigen-binding compounds have a degree ofselectivity for its cellular targets and can deplete KIR-expressing Tcells via NK-cell mediated ADCC. Moreover, NK cell-mediated ADCCactivity can be augmented to high levels by modifying the Fc region ofthe antibody.

In another embodiment, encompassed is an isolated antigen-bindingcompound, e.g. an antibody, that specifically binds an epitope presenton a KIR3DL2 polypeptide and inhibits proliferation ofKIR3DL2-expressing cells, e.g. human T lymphocytes, tumor cells, and Tlymphocyte tumor cells. In one embodiment, the invention provides anisolated antigen-binding compound that specifically binds an epitopepresent on a KIR3DL (e.g. KIR3DL1 or KIR3DL2) polypeptide and inducesKIR3DL (e.g. KIR3DL1 or KIR3DL2) signaling on a KIR3DL-expressing cell,e.g. a T lymphocyte. Such compounds can be used to inhibit theproliferation or activity (e.g. proinflammatory activity, cytokineproduction) of tumor cells or cells involved in autoimmunity orinflammation, e.g. T cells.

In another aspect, the invention provides an isolated antigen-bindingcompound that specifically binds an epitope present on a KIR3DL (e.g.KIR3DL1 or KIR3DL2) polypeptide and induces KIR3DL (e.g. KIR3DL1 orKIR3DL2) signaling in a KIR3DL-expressing cell, wherein the compounddoes not substantially induce ADCC of a KIR3D-expressing target cell.Examples of such a compound include antibodies that do not comprise anFc region that has substantial binding to Fc receptors such as CD16,e.g. antibodies comprising an Fc region that has low or no binding to Fcreceptors such as IgG4 isotypes or IgG isotypes modified to decreasebinding to Fc receptors. Such compounds can be used to inhibit theproliferation of activity (e.g. proinflammatory activity, cytokineproduction) of cells involved in autoimmunity or inflammation, e.g. Tcells, without killing the cells. In one embodiment, the inventionprovides an antigen-binding compound that binds an Ig-like domain 0 ofSEQ ID NO 21. Optionally said antigen-binding compound binds domain 0 ofSEQ ID NO 21 selectively compared to KIR3DL2 domain 1 of SEQ ID NO 22 orKIR3DL2 domain 2 of SEQ ID NO 23. Preferably, the binding compound bindsdomain 0 of SEQ ID NO 21 with a binding affinity that is at least 1-log,2-log, 3-log or 4-log greater (optionally a dissociation constant (KD)of at least 1-log, 2-log, 3-log or 4-log less) than its binding to aKIR3DL2 domain 1 of SEQ ID NO 22 or KIR3DL2 domain 2 of SEQ ID NO 23.Optionally, said compound does not substantially bind Ig-like domain 1of SEQ ID NO 22 and/or Ig-like domain 2 of SEQ ID NO 23. In one aspect,any of the antigen-binding compounds of the invention binds a commondeterminant present on KIR3DL1 and KIR3DL2, preferably a commondeterminant present in domain D0 of KIR3D receptors. Optionally, in anyof the embodiments, the antigen-binding compound induces signaling by aKIR3DL polypeptide. In one aspect, any of the antigen-binding compoundsof the invention binds a common determinant present on KIR3DL2 andKIR3DS1. Optionally, said antigen-binding compound binds a commondeterminant present on KIR3DL1, KIR3DL2 and KIR3DS1. Optionally saidKIR3DL2 is a monomer or a homodimer, e.g. present on the surface of acell such as an NK cell, T cell, or a cell transfected with DNA encodingKIR3DL2 polypeptides. Preferably said KIR3D polypeptide(s) is a humanpolypeptide.

Significantly, in certain embodiments, since antigen-binding compoundsthat bind a KIR3DL2 polypeptide, particularly in the case whenantibodies are used, will not depend exclusively on immune cell mediatedcell killing (e.g. ADCC), it is expected that antigen-binding compoundsthat bind a KIR3DL2 polypeptide can be used effectively in patientshaving a deficient or suppressed immune system, and/or in combinationwith additional anti-tumor agents or anti-inflammatory agents,particularly therapeutic agents which are known to have adverse impactson the immune system. For example, immunocompromised patients (e.g.,with HIV infection), patients taking anti-inflammatory orimmunosuppressive drugs (e.g., subsequent to transplantation or astreatment for autoimmune disorders, agents for the treatment of anautoimmune or inflammatory conditions), or patients takingchemotherapeutic agents are particularly good candidates for treatmentwith such compounds.

Additionally, since antigen-binding compounds of the invention that binda KIR3DL2 polypeptide and have an ADCC or anti-proliferative effect caneradicate or stop the growth of proliferating cells, it may be desirableto combine the antigen-binding compounds disclosed herein with otheranti-proliferative and/or ADCC agents in the in vitro and in vivomethods provided herein, such that the respective ADCC or anti-cellproliferation activities are enhanced, and also so that the cells canbe, e.g., first subjected to growth arrest and then eradicated by theADCC compounds.

In a preferred embodiment, the antigen-binding compound of any of theembodiments herein is “naked” and is not functionalized with aradioactive isotope, toxic peptide or toxic small molecule (e.g. a“naked” antibody). In another embodiment, the antigen-binding compoundis a cytotoxic antigen-binding compound and comprises an elementselected from the group consisting of radioactive isotope, toxicpeptide, and toxic small molecule. In another embodiment, theradioactive isotope, toxic peptide, or toxic small molecule is directlyattached to the antigen-binding compound.

Preferably the antigen-binding compound binds to the same epitope on aKIR3DL polypeptide (e.g. KIR3DL2) as antibody chAZ158. In oneembodiment, the antigen-binding compound competes for binding withantibody chAZ158 to a KIR3DL2 polypeptide (e.g. to an isolatedpolypeptide or to a cell expressing it). Optionally, the antigen-bindingcompound further competes for binding with antibody chAZ158 to a KIR3DL1and/or KIR3DS1 polypeptide. In any of the embodiments herein, theantigen-binding compound specifically binds to malignant human CD4+ Tcells. In any of the embodiments herein, the antigen-binding compoundcauses the elimination of malignant human KIR3DL2-expressing CD4+ Tcells. In any of the embodiments herein, the antigen-binding compoundinhibits the proliferation of malignant human KIR3DL2-expressing CD4+ Tcells. Optionally the CD4+ T cells are from individuals having SézarySyndrome or Mycosis Fungoides, or from individuals having an autoimmuneor inflammatory condition.

In another embodiment, the antigen-binding compound of any of theembodiments herein is an antibody, e.g., a bivalent chimeric orhumanized antibody. In one such embodiment, the antibody comprises thevariable (antigen-binding) domains of antibody chAZ158, e.g. thevariable regions or part of all of the CDRs of chAZ158.

In another embodiment of any of the embodiments herein, the antibodiesare not substantially internalized by KIR3DL2-expressing cells, e.g.,Cou-L cells, and as such are capable of inducing cell mediated killing(ADCC) of target (KIR3DL2-expressing) cells.

In one aspect of any of the embodiments herein, the antibody comprisesan Fc tail, optionally an Fc tail that is hypofucosylated. In oneembodiment the invention provides an antibody composition comprising aplurality of antibodies according to any of the embodiments herein,wherein at least 40% of antibodies have a common N-linkedoligosaccharide structure of a biantennary type that comprises longchains with terminal GlcNac that are highly galactosylated andnon-fucosylated.

In one aspect of any of the embodiments herein, the anti-KIR3DL2antibodies have a binding affinity to KIR3DL2-epitopes, preferably theepitope specifically recognized by chAZ158, on e.g. KIR3DL2, of 50, 40,30, 20, 10, 5, 1, or less nanomoles. In other preferred embodiments, theantibody is an antibody other than murine AZ158, Q66 or Q241, each ofwhich are antibodies having murine Fc regions, or having non-human Fcregions.

Accordingly, the present invention provides a method of treating apatient with a T cell lymphoma, e.g. CTCL, SS, MF, the method comprisingadministering to the patient a pharmaceutically effective amount of anantigen-binding compound according to the invention that specificallybinds to a KIR3DL2 polypeptide.

In another embodiment, the present invention provides a method oftreating a patient with an autoimmune or pro-inflammatory disordermediated at least in part by KIR3D-expressing T cells, the methodcomprising administering to the patient a pharmaceutically effectiveamount of an antigen-binding compound according to the invention thatspecifically binds to a KIR3D polypeptide.

The present invention also provides a method of treating a patient, themethod comprising:

a) determining whether the patient has pathogenic KIR3DL-expressingcells, optionally KIR3DL-expressing CD4+ T cells, and

b) if the patient is determined to have pathogenic KIR3DL-expressingcells, administering an antigen-binding compound (e.g., antibody) of theinvention that specifically binds a KIR3DL (e.g. KIR3DL2) polypeptideand that is capable of inducing ADCC and/or inhibiting the activity,growth or proliferation of a KIR3DL-expressing cell. Preferably, theantigen-binding compound activates KIR3DL (e.g. KIR3DL2).

In one embodiment, the invention provides a method of producing anantigen-binding compound, said method comprising: i) providing anantigen-binding compound that specifically binds to a KIR3D polypeptide,optionally by immunizing a non-human animal with a KIR polypeptide or byproducing a library of antigen-binding compounds, ii) testing theability of the antigen-binding compound for binding to an epitope withindomain 0 of a KIR3D polypeptide and to an epitope within domain 1 and/or2 of a KIR3D polypeptide; iii) selecting the antigen-binding compound ifit is determined that the antigen-binding compound binds to an epitopewithin domain 0 of a KIR3D polypeptide but not within domains 1 and/or 2of a KIR3D polypeptide; and optionally iv) testing the ability of theantigen-binding compound to modulate an activity of the KIR3Dpolypeptide and selecting the antigen-binding compound if it isdetermined that the antigen-binding compound modulates an activity ofthe KIR3D polypeptide. The method may optionally further comprise a stepof producing a quantity of the selected antigen-binding compound.

In one embodiment, the invention provides a method of producing anantigen-binding compound suitable for use in the treatment of disorderscharacterized by pathogenic KIR3DL-expressing cells, said methodcomprising: i) providing an antigen-binding compound that specificallybinds to a KIR3DL2 polypeptide, ii) testing the ability of theantigen-binding compound for ADCC (e.g. in a cytoxicity assay) and/oractivation of KIR3DL (e.g. in a cell proliferation assay, signaltransduction assay); iii) selecting the antigen-binding compound if itis determined that the antigen-binding compound has ADCC and/oractivates KIR3DL; and optionally iv) producing a quantity of theselected antigen-binding compound. In one embodiment, the compoundselected in step iii) is an antibody and is made suitable for humanadministration prior to step iv), for example by humanizing orchimerizing it. Optionally, a plurality of antigen-binding compounds areprovided in step i), and they are each tested in step ii) for theirability to induce ADCC and/or activate KIR3DL or inhibit theproliferation of a cell expressing a KIR3DL polypeptide. Typically, stepii) will involve standard assays in which cells, e.g. KIR3DL-expressingcells, will be contacted with the compound and the proliferation,survival and/or activity (KIR signal transduction, proliferation) of thecells will be assessed. When testing ADCC, step ii) may involve standardassays where ability of the antibody to induce NK cell mediatedcytotoxicity, markers of NK cell activation, of the KIR3DL-expressingcells is tested. The cells may be for example T lymphoma cells such asCou-L cells, cells taken from a patient with a T cell malignancy or a Tcell mediated autoimmune or inflammatory disorder, e.g. CD4+CD28− Tcells. In preferred embodiments, the antigen-binding compound is anantibody; optionally the antibody is an IgG. Additionally, the antibodyis preferably bivalent. Preferably the antibody selected induces atleast 30, 40 or 50% lysis of KIR3DL-expressing target cells in acytoxocity assay. In preferred embodiments, the antibody is IgG.Additionally, the antibody is preferably bivalent (and comprises an Fctail). In other preferred embodiments, the antibody is hypofucosylated.

In another embodiment, the invention provides a method of producing anantigen-binding compound suitable for use in the treatment of a disordercharacterized by pathogenic KIR3DL-expressing cells, said methodcomprising: i) producing a quantity of an antigen-binding compound thatspecifically binds to a KIR3DL2 polypeptide, ii) testing a sample fromsaid quantity of antigen-binding compound for ADCC and/or activation ofKIR3DL (e.g. in a cell proliferation assay, signal transduction assay);iii) selecting the quantity for use as a medicament and/or in themanufacture of a medicament if it is determined that the antigen-bindingcompound has ADCC and/or KIR3DL signaling activity; and optionally iv)preparing the quantity for administration to a human, optionallyformulating a quantity of the selected antigen-binding compound with apharmaceutically acceptable carrier.

In another embodiment, the invention provides a method of producing anantigen-binding compound, comprising: i) providing an antigen-bindingcompound that specifically binds to cells expressing a KIR3DL (e.g.KIR3DL2) polypeptide taken from one or more patients with a disordercharacterized by pathogenic KIR3DL-expressing cells; ii) testing theantigen-binding compound for ADCC and/or activation of KIR3DL (e.g.KIR3DL2) in cells taken from one or more patients with a disordercharacterized by a pathogenic expansion of KIR3DL-expressing cells, e.g.T cell lymphoma, SS or MF, an inflammatory or autoimmune disorder; iii)if the antigen-binding compound induces ADCC towards or activates KIR3DLin a substantial number of KIR3DL-expressing cells taken from one ormore of the patients, making the antigen-binding compound suitable forhuman administration; and iv) optionally producing a quantity of thehuman-suitable antigen-binding compound.

In one embodiment of any of the methods of the invention, the method maycomprise a step of immunizing a non-human mammal (e.g. a mouse, rat,rabbit, mouse transgenic for human Ig genes, etc.) with a KIR3DLpolypeptide (e.g. a purified polypeptide or a cell expressing thepolypeptide) prior to step i). In another embodiment, the methodcomprises a step of generating a library of antigen-binding compounds(e.g. via phage display methods and the like) and selecting anantigen-binding compound that binds KIR3DL polypeptide prior to step i).

In one embodiment of any of the methods of the invention, theantigen-binding compound or antibody of step i) and/or step ii) does notcomprise a cytotoxic agent such as a radioactive isotope, a toxicpolypeptide, or a toxic small molecule.

Testing the ability of each of the antigen-binding compound orantibodies to induce ADCC of a cell or to activate KIR3DL2 in a cell(e.g. inhibit the cell's proliferation) can be carried out according toany of a variety of available methods. For example, testing ADCC maycomprise without limitation detecting death (e.g. lysis, cytokineproduction, mobilization of cytoxicity markers) of a target cell (e.g.malignant cell, Cou-L cell, cell expressing a KIR3DL2 polypeptide) orincreases and/or decreases in cytokines or generally proteins involvedin ADCC. Testing for activation of KIR3DL2 may comprise withoutlimitation detecting cell growth inhibition or phosphorylation of signaltransduction components such as SHP-1. For example, any of the assays inthe Examples section herein can be used. Optionally, testing activationof KIR3DL2 is carried out in the absence of immune effector cells,particularly NK cells.

In one embodiment of any of the methods of the invention, making theantigen-binding compound suitable for administration to a humancomprises making an anti-KIR3D antibody chimeric, human, or humanized.Making the compound suitable for administration to a human can alsocomprise formulating the compound with a pharmaceutically acceptablecarrier.

In one embodiment of any of the methods of the invention, producing aquantity of antigen-binding compound comprises culturing a cellexpressing the antigen-binding compound in a suitable medium andrecovering the antigen-binding compound. Optionally, the cell is arecombinant host cell made to express the antigen-binding compound. Inone embodiment, the compound is a monoclonal antibody and the cell is ahybridoma.

In one embodiment of any of the methods of the invention, theantigen-binding compound, particularly the antigen-binding compoundproduced by the method does not comprise a cytotoxic agent such as aradioactive isotope, a toxic polypeptide, or a toxic small molecule. Inone embodiment, the antigen-binding compound is an antibody thatspecifically binds a KIR3D polypeptide. In one embodiment of any of themethods of the invention, the antigen-binding compound competes forbinding with antibody chAZ158 to a KIR3D polypeptide. In one embodimentof any of the methods of the invention, the compound is an antibodyother than AZ158. In another embodiment of any of the methods of theinvention the compound is a chimeric, human, or humanized antibody.

In one embodiment of any of the methods of the invention, theantigen-binding compound, preferably an antibody, has an Fc receptorbinding portion, preferably a heavy chain constant region of an IgGisotype, optionally of a human IgG isotype. In a preferred embodiment,the antibody is an IgG1 antibody; such antibodies will be able tomediate ADCC and/or crosslink KIR3DL receptors so as to induce receptorsignaling. The invention also encompasses fragments and derivatives ofantibodies having substantially the same antigen specificity andactivity (e.g., which can bind to the same antigens as the parentantibody). Such fragments include, without limitation, Fab fragments,Fab′2 fragments, CDR and ScFv. When the compound is an antibody, theantibody will typically be, for example, chimeric, humanized or human.In one preferred embodiment, the antibody is a recombinant chimericantibody.

In certain embodiments, the compounds of the invention are multimeric(i.e. cross-linked) IgG antibodies. In preferred embodiments, theantibodies are tetrameric (two heavy and two light chains) and are thusbivalent. In particularly preferred embodiments, the antibodies arecapable of inducing ADCC or activating KIR3DL (e.g. KIR3DL2). In otherparticularly preferred embodiments, the antibodies are capable ofinducing KIR3DL signaling in cells expressing KIR3DL, and are also ableto induce ADCC of cells expressing KIR3DL. In other preferredembodiments, the antibodies are capable of inducing at least 20%, 30%,40% or 50% cell lysis in a cytoxicity assay, e.g. of cells from SSpatients or SS cell lines (e.g., Cou-L cells).

In another embodiment, the invention encompasses an antigen-bindingcompound produced according to any of the methods of the invention.

The invention also encompasses pharmaceutical formulations comprisingany of the antigen binding compounds and in particular any of theantibodies of the invention and a pharmaceutically acceptable carrierare also provided, as are kits. Kits may for example comprise thecompound and instructions for its use and/or a carrier composition,e.g., in the treatment of CTCL, autoimmune or inflammatory disorders.Kits may comprise the compound and a carrier; kits may comprise thecompound in a manufactured (e.g. glass, plastic or other) container.Cells expressing the antibodies, e.g., hybridomas, are also encompassed.

In one embodiment, the antigen-binding compound or antibody of theinvention competes for binding with antibody chAZ158 to a KIR3DL2polypeptide. The invention also encompasses fragments and derivatives ofthe antibodies having substantially the same antigen specificity andactivity as antibody chAZ158 (e.g., which can bind to the same antigensas the parent antibody). Such fragments include, without limitation, Fabfragments, Fab′2 fragments, CDR and ScFv.

Accordingly, in another embodiment, the invention provides an antibody,preferably an isolated antibody, which binds to a KIR3DL2 polypeptideand which is capable of inducing ADCC and/or activating KIR3DL2 in acell which expresses a KIR3DL2 polypeptide, wherein the antibodycompetes for binding with antibody chAZ158 to a KIR3DL2 polypeptide.

In another embodiment, the invention provides a bivalent antibodycomprised of two heavy chains and two light chains, wherein the heavychains comprise an IgG heavy chain constant region capable of binding toan Fc receptor, and wherein the antibody: (a) is capable of activatingKIR3DL in cells (e.g. inhibiting the proliferation of the cells,receptor signaling) expressing a KIR3DL polypeptide; (b) is capable ofinducing cell-mediated killing (ADCC) of KIR3DL-expressing cells; and(c) competes for binding with antibody chAZ158 to a KIR3DL polypeptide.

In another embodiment, the invention provides a bivalent antibodycomprising: (a) a heavy chain comprising a variable region comprisingone or more CDRs derived from the amino acid sequence of SEQ ID NO: 8fused to a human IgG chain constant region; and (b) a light chaincomprising a variable region comprising one or more CDRs derived fromthe amino acid sequence of SEQ ID NO: 10, optionally fused to a humankappa chain constant region.

In another embodiment, any of the antibodies herein can further becharacterized as having a heavy chain constant region of an IgG isotype,optionally of a human IgG or IgG1 isotype. In another embodiment, any ofthe antibodies herein can further be characterized by being tetrameric.In another embodiment, any of the antibodies herein can further becharacterized as being bivalent. In another embodiment, any of theantibodies herein can further be characterized as being a chimeric,human or humanized antibody. In another embodiment, any of theantibodies herein can further be characterized as being hypofucosylated.

The invention also encompasses a cell expressing any of theantigen-binding compounds of the invention. In one aspect the cell is ahybridoma which produces an antibodies of the invention. In anotheraspect the cell is a recombinant host cell which produces an antibody ofany one of the preceding claims. Optionally the host cell is an aviancell, preferably a chicken or duck cell, preferably further an avianembryonic derived stem cell line. Optionally the cell producesantibodies having hypofucosylated Fc regions. The invention alsoencompasses methods of producing an antibody comprising culturing a hostcell and recovering the antibody produced by said host cell.

The invention also encompasses a pharmaceutical composition comprisingany of the herein-described antigen-binding compounds or antibodies, anda pharmaceutically acceptable carrier. In another aspect, the inventionencompasses a kit comprising an antigen-binding compound or an antibodyof the invention, and instructions for using said antigen-bindingcompound or antibody in the treatment or diagnosis of aKIR3DL-expressing pathology. In another embodiment, cells, e.g.,hybridomas, are also provided. In another aspect, the inventionencompasses a method of treating an individual (e.g. a human) having adisorder characterized by KIR3D (e.g. KIR3DL2) expressing cells,particularly a T cell malignancy, a cardiovascular disorder, anautoimmune disorder or an inflammatory disorder, the method comprisingadministering to said individual an antigen-binding compound, antibodyor pharmaceutical composition of the invention.

In other aspects, provided is a method of inducing the ADCC and/orinhibiting the activity or proliferation of a pathogenicKIR3DL-expressing cell, and/or of treating a patient or individual witha disorder selected from the group consisting of a T cell malignancy, anautoimmune disorder and an inflammatory disorder, the method comprising:a) determining if a pathogenic KIR3DL-expressing cell is suitable fortreatment with an ADCC and/or KIR3DL activating agent, and b) in thecase of a positive determination that the pathogenic KIR3DL-expressingcell is suitable for treatment with an ADCC and/or KIR3DL activatingagent, contacting the pathogenic KIR3DL-expressing cell with aneffective amount of any of the antigen-binding compounds of theinvention. In yet another aspect, the invention provides a method ofinducing the ADCC and/or inhibiting the activity or proliferation of apathogenic KIR3DL-expressing cell, and/or of treating a patient orindividual with a disorder selected from the group consisting of a Tcell malignancy, an autoimmune disorder and an inflammatory disorder,the method comprising: a) determining if pathogenic cells (e.g. CD4+ Tcells, CD4+ T lymphoma cells, CD4+ cells involved in inflammation orautoimmunity) from the patient express a KIR3DL polypeptide, and b) inthe case of a positive determination that pathogenic cells express aKIR3DL polypeptide, contacting pathogenic cells with an effective amountof an antigen-binding compound of any one of the above claims.Optionally, in these methods, the step of contacting the pathogeniccells comprises administering to the patient a pharmaceuticallyeffective amount of an antigen-binding compound of the invention.Preferably, the pharmaceutically effective amount is an amount effectiveto induce ADCC or inhibit the activity or proliferation of pathogeniccell(s) in the patient. In certain embodiments, in assessment ofinhibition of cell proliferation the contacting is carried out in theabsence or relative paucity of immune effector cells, e.g., NK cells,for example when such methods are carried out in vitro or when they arecarried out in patients with deficient immune systems (e.g., due toconditions such as AIDS, to conditions that decrease NK cell levels, tothe administration of chemotherapeutic agents, or to the use ofimmunosuppressive agents, for example in conjunction with atransplantation procedure or treatment of autoimmune disorders).

In another aspect, the invention provides a method of inducing the ADCCof and/or inhibiting the activity or proliferation of a KIR3DLpolypeptide-expressing cell, comprising bringing said cell into contactwith an antigen-binding compound of the invention in an amount effectiveto induce ADCC and/or inhibit the activity or proliferation of the cell.Optionally, when inhibiting cell proliferation directly (i.e. inducingKIR signaling), said bringing into contact is in the absence or relativepaucity of immune effector cells, e.g., NK cells, and/or is carried outin vitro. Optionally the method further comprises determining whetherthe antigen-binding compound is capable of inducing ADCC and/orinhibiting the proliferation of the cell. Optionally, the compound is anantibody that is capable of inducing the cell-mediated killing (ADCC) ofKIR3DL-expressing cells, in the presence of immune effector (e.g., NK)cells.

These and additional advantageous aspects and features of the inventionmay be further described elsewhere herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 to 3 together show three series of treatments of C57B16 micebearing B16 melanoma cells with AZ158 on days −1, 1, 5 and 7, asassessed by counting the number of lung metastases at day 20. Results inFIGS. 1 to 3 demonstrate that AZ158 decreased the number of metastasessignificantly compared to mice not receiving AZ158.

FIGS. 4A-4B show the staining patterns for PBMC from a healthy donorgated on CD3⁻ CD56⁺ (NK lymphocytes), incubated with mAbs PE-DX9, PE-Z27(FIG. 4A) and PE-AZ158 (FIG. 4B), washed and labeled.

FIGS. 5A-5B show the staining patterns for PBMC from a healthy donorgated on CD3⁺ (T lymphocytes), incubated with mAbs PE-DX9, PE-Z27 (FIG.5A) and PE-AZ158 (FIG. 5B), washed and labeled.

FIG. 6 shows the sensorgrams for the binding of chAZ158 to KIR3DL2(black; upper line) and KIR3DL1 (grey; lower line) chips, superimposed,with resonance units (RU) on the y-axis and time (seconds) on thex-axis.

FIGS. 7-10 show staining to untransfected cells (FIG. 7) or cellstransfected with DNA encoding the extracellular domain 0 (FIG. 8),domain 1 (FIG. 9) or domain 2 (FIG. 10) of the KIR3DL2 molecule, in eachcase linked to DNA encoding the CD24-GPI anchor. V5-FITC staining isindicated on the y-axis and chAZ158-GAH-PE on the x-axis. The figuresshow that chAZ158 binds to cells expressing domain 0 but not to cellsexpressing domains 1 or 2.

FIG. 11 shows a direct effect on Cou-L cells (Sézary Syndrome cells;KIR3DL2 positive) in a cell proliferation assay where Cou-L cells werecultured with chAZ158 antibody, a chimeric isotypic control produced inthe same conditions or anti-Class I antibody. Results show that chAZ158has a strong direct inhibitory effect on Cou-L cell proliferation.

FIG. 12 shows chAZ158-induced IFN-γ production by human NK cells againstCou-L cell targets. ChAZ158 produced by EB14 or EBX cells showed astrong increase of IFN-γ producing NK cells compared to chAZ158 producedby CHO.

FIG. 13 shows chAZ158-induced CD107 mobilization by human NK cellsagainst Cou-L cells. ChAZ158 produced by EB14 or EBX cells showed astrong increase in percentages of CD107 positive NK cells compared tochAZ158 produced by CHO.

FIG. 14 shows chAZ158-induced induced specific lysis of Cou-L cells byhuman NK cells. ChAZ158 produced by EB14 or EBX cells showed a strongincrease in percentages of specific lysis compared to chAZ158 producedby CHO.

FIG. 15 shows chAZ158-induced IFN-γ production by heterologous NK cellsagainst Sézary syndrome patient PBMC. ChAZ158 produced by EBX cellsinduced a strong increase in IFN-γ producing NK cells compared to NKcells in the absence of chAZ158.

FIG. 16 shows chAZ158-induced CD107 mobilization by heterologous NKcells against Sézary syndrome patient PBMC. ChAZ158 produced by EBXcells induced a strong increase in CD107 positive NK cells compared toNK cells in the absence of chAZ158.

DETAILED DESCRIPTION OF THE INVENTION Introduction

The present invention results, inter alia, from the discovery thatantigen-binding compounds that bind KIR3DL2 polypeptides are able toslow the proliferation of KIR3DL2-expressing CD4+ T cells. TheKIR3DL2-binding compounds of the invention are capable of directlyinhibiting the proliferation of KIR3DL2-expressing cells, particularlyCD4+ T cells, in the absence of effector cells, accessory cells, orcompositions having co-stimulatory function. This inhibition is believedto occur as a result of the activation of KIRDL2 signalling by theantigen-binding protein, whereby the KIR3DL2 protein transmits aninhibitory signal with the net result of inhibiting cell growth. Thefinding is surprising in part because there have not been any reports ofCD4+ T cells with functional inhibitory KIR, and also becauseKIR-mediated signalling has until now, in CD8+T and NK cells, beeninvolved in regulating effector cell cytotoxicity and not cellproliferation. The knowledge of KIR signalling in CD4+ T cells has beenlimited to activatory KIR (e.g. KIRDS polypeptides), and these have beenreported only to have a co-activatory role, rather than the trueactivatory role in NK cells. The lack of true activatory function wasreported to be due to missing “DAP12” signalling adaptors in T cells. Itwas furthermore discovered that the anti-KIR3DL2 antibodies thatinhibited cell proliferation directly were additionally capable ofmediating ADCC toward KIR3DL2-expressing cells when containing Fcportions that bind Fc receptors. The anti-KIR3DL2 antibodies werefurthermore capable of binding their target with high affinity even whenpresent in a less than decavalent (e.g. as would be the case for an IgM)form. Notably, KIR3DL2 antibodies of the invention in bivalent form werecapable of mediating ADCC of KIR3DL2-expressing cells, demonstratingthat they are of substantially high affinity.

The particular antibodies disclosed herein bind a common determinant orepitope shared by the monomeric KIR3DL1 and KIR3DS1 and the dimericKIR3DL2. The identification that the antibodies are capable of actingdirectly on KIR3DL2, e.g. to transmit an inhibitory signalintracellularly, in a KIR3DL2-expressing T cell indicates that theantibody will be suitable to increase therapeutic activity compared toother anti-KIR3DL2 antibodies. The antibody's anti-KIR3DL1 bindingability may provide further therapeutic activity in the treatment, e.g.of CD4+ T cells that express KIR3DL1, where the antibody may directlyinhibit KIR3DL1-mediated proliferation and/or cytokine production orcytotoxicity, as well as mediate ADCC-mediated elimination ofKIR3DL1-expressing cells.

It was also observed, independently of any effect of inhibition ofproliferation, that the antibodies' ability to mediate ADCC towardKIR3DL2-expressing cells could be significantly improved by modificationof the Fc portion of the antibody by producing it in a cell line whichgenerates antibodies having a glycosylation profile different from e.g.typical CHO cell lines used to produce therapeutic recombinantantibodies. These modified Fc portions are hypofucosylated, believed toincrease their binding to Fc receptors, e.g. Fcγ receptors on effectorcells.

Importantly, the compounds of the invention are able to directly targetKIR3D-expressing CD4+ T cells, particularly KIR3DL-expressing cells, andinhibit their activity, and in particular inhibit their proliferation.Significantly, as these effects depend solely on the interaction of thecompound with the KIR3DL polypeptide, they can occur with “naked”compounds (particularly antibodies), i.e. compounds that have not beenmodified or derivatized with toxic compounds. Further, when thecompounds are antibodies, they can effectively target tumor cells evenwithout relying on immune cell mediated killing of the tumor cells(ADCC) (although it should be emphasized that ADCC can also take placein many contexts, further enhancing the efficacy of the treatment).Accordingly, the present compounds are particularly useful for patientswith a compromised immune system, e.g., patients with AIDS, patientstaking chemotherapy, or patients taking immunosuppressive drug regimens.

Although the compounds of the invention can be any type of molecularentity (e.g. polypeptide, small molecule) that can specifically bind toKIR3DL2-expressing cells and thereby inhibit their growth andproliferation, preferred compounds of the invention are antibodies. Thecompounds will preferably act as agonists at KIR3DL2, e.g. as may bepresent on CD4+ T cells, where the agonism of KIR3DL2 results in a netinhibition of proliferation or other activity (e.g. cytokine production,cytotoxicity) of the cell. Particularly preferred antibodies arebivalent IgG antibodies, as they can typically not only directlydecrease target cell numbers by inhibiting cell proliferation, but alsocomprise Fc tails and have sufficient binding affinity to induce thekilling of the cells through ADCC. Accordingly, by selecting the properantibodies (bivalent IgG antibodies that target KIR3DL2 having modifiedFc tails, most preferably the KIR3DL2 epitope recognized by antibodychAZ158), it is possible to target KIR3DL2-expressing tumor cellsthrough two independent mechanisms (growth inhibition and ADCC).Together, these discoveries therefore provide unexpected ways to produceparticularly efficacious antigen-binding compounds, most preferablyantibodies, that have, inter alia, desired ADCC or anti-cellproliferation properties as well as, typically, ADCC-inducing effects.Methods of producing and using such antigen-binding compounds, as wellas exemplary antigen-binding compounds, are described.

The invention provides methods of using the antigen-binding compounds;for example, the invention provides a method for inhibiting cellproliferation or activity and/or inducing ADCC, comprising exposing acell, such as a T cell which expresses a KIR3DL polypeptide, to anantigen-binding compound that binds a KIR3DL2 polypeptide in an amounteffective to induce ADCC and/or inhibit cell proliferation. It will beappreciated that for the purposes of the present invention, “cellproliferation” can refer to any aspect of the growth or proliferation ofcells, e.g., cell growth, cell division, or any aspect of the cellcycle. The cell may be in cell culture or in a mammal, e.g. a mammalsuffering from a KIR3DL-expressing pathology. The invention alsoprovides a method for inducing ADCC of or inhibiting the proliferationof a cell which expresses a KIR3DL polypeptide, comprising exposing thecell to an antigen-binding compound (e.g. exogenous antibody) that bindsa KIR3DL2 polypeptide as described herein in an amount effective toinduce ADCC or inhibit the proliferation of the cell. Thus, theinvention provides a method for treating a mammal suffering from acondition characterized by a pathogenic expansion of cells expressing aKIR3DL polypeptide, e.g. KIR3DL1 or KIR3DL2, comprising administering apharmaceutically effective amount of an antigen-binding compounddisclosed herein to the mammal. Examples of such conditions includeSézary Syndrome, Mycosis Fungoides, CTCL, and autoimmune or inflammatoryconditions, e.g. arthritis, cardiovascular disease. In preferredembodiments, the compound is an antibody, e.g. a bivalent IgG antibodyand is effective at inducing ADCC of the cells.

The present invention provides methods for producing antigen-bindingcompounds, particularly antibodies, that specifically bind a KIR3DL2polypeptide and that are useful for the treatment of T cell lymphomas(e.g. CTCL, Sézary Syndrome and Mycosis Fungoides), autoimmune disordersand inflammatory disorders, particularly when mediated at least in partby CD4+ T cells. The antigen-binding compounds produced using thepresent methods are capable of specifically targeting T lymphoma cellsor other cells expressing a KIR3DL polypeptide, particularly an epitopeon a KIR3DL2 polypeptide recognized by antibody chAZ158. Theantigen-binding compound can limit the pathological effects of cellproliferation and/or activity by inhibiting the proliferation oractivity of the cells and/or by targeting them for destruction by theimmune system (e.g., via ADCC).

Several KIR3DL-expressing disorders, particularly T cell mediateddisorders, can be treated using the methods and compositions of theinvention. The disorders may be for example CD4+ T cell malignanciessuch as CTCL, MF or SS, or autoimmune or inflammatory disorders wherethe elimination or inhibiting the activity and/or proliferation of CD4+T cells would be useful. CD4+ T cells include for example activated CD4+T cells, CD4+ T cells expressing or not one or more other markers (e.g.CD2+, CD3+, CD5+, CD8−, CD28⁺, CD28⁻, CD45RO+ and TCRαβ+). CD4+CD28− Tcells, for example, are known to express KIR3DL and are present in highfrequencies of clonally expanded cells in some autoimmune andinflammatory disorders but are rare in healthy individuals. These Tcells can be cytotoxic, secrete large amounts of IFN-gamma, andproliferate upon stimulation with autologous adherent mononuclear cells.

Cutaneous and circulating MF/SS cells have been reported to not expresspreferential alleles among nine KIR3DL2 alleles tested. Thirteen alleleshave also been described to date. Whereas the p140-KIR3DL2 receptor isexpressed on a minor subset of NK cells and on rare CD8+ T cells inhealthy persons, it appears to be restricted to CTCL tumor CD4+ T cellsin MF/SS patients. Other receptors that are usually observed at thesurface of NK cells (such as p58.1, p58.2, p70KIRs, CD94/NKG2A) are notfound at the surface of malignant CD4+ T cells (Bahler D. W. et al.(2008) Cytometry B Clin Cytom. 74(3):156-62). SS cells are alsotypically characterized, in addition to CD4+, by having a mature Tlymphocyte phenotype, CD2+, CD3+, CD5+, CD8−, CD28+, CD45RO+ and TCRαβ+.

The methods and compositions of the invention can also be used in thetreatment of autoimmune and inflammatory conditions characterized byKIR3DL expression. For example, it has been shown that several suchdisorders are mediated at least in part by CD4+ T cells, includingparticular CD4+CD28null T cells. Activation of CD4+ T cells is generallythought to be governed by interplay between stimulatory and inhibitoryreceptors, where a predominance of stimulatory signals favors autoimmunereactions. Chan et al. (2005) Arthrit. Rheumatism 52(11): 3586-3595report that increased numbers of peripheral blood and synovial fluidCD4+ T cells and NK cells express KIR3DL2 in spondylarthritis. Inpatients with rheumatoid arthritis, expression of the criticalcostimulatory molecule, CD28, is frequently lost. Instead, a CD4⁺ T cellpopulation which lacks CD28 (CD4⁺CD28⁻ T cells) express killerimmunoglobulin-like receptors (KIRs). CD4+CD28^(null) T cells inparticular have been reported to express KIR3D polypeptides. Comparedwith their CD28⁺ counterparts, CD4+CD28− cells produce significantlyhigher levels of IFN-γ giving them the ability to function asproinflammatory cells. CD4⁺CD28^(null) T cell clones persist for yearsin circulation. These T cells are known to differ from CD28⁺ T cells bybeing resistant to Fas-mediated apoptosis upon cross-linking of CD3.CD28^(null) T cells progress through the cell cycle, and cells at allstages of the cell cycle are resistant to apoptosis, unlike their CD28⁺counterparts. Dysregulation of apoptotic pathways in CD4⁺CD28^(null) Tcells has been shown to favor their clonal outgrowth and maintenance invivo. Namekawa et al. (2000) J. Immunol. 165:1138-1145 report that KIR,including KIR3DL2, was present on CD4⁺CD28null T cells expanded inrheumatoid arthritis. Rheumatoid arthritis involves lymphocyteinfiltrates, inflammatory mediators, and synovial hyperplasia resultingfrom aggressive proliferation of fibroblast-like synoviocytes andmacrophages. Prognoses of joint erosions and disease severity correlatewith high frequencies of clonally expanded CD4⁺CD28⁻ T cells. Lamprechtet al. (2001) Thorax 56:751-757 report recruitment of CD4⁺CD28⁻ T cellsin Wegener's granulomatosis. Markovic-Plese et al. (2001) J Clin Invest.108: 1185-1194 report the presence of CD4+CD28−costimulation-independent T cells in the CNS, and their association withmultiple sclerosis. The methods and compositions of the invention cantherefore be used in the treatment or prevention of Wegener'sgranulomatosis, multiple sclerosis or other central nervous systeminflammatory or autoimmune disorders, arthritis, or other rheumaticdisorders characterized by inflammation.

CD4⁺CD28⁻ T cells have also been associated with cardiovasculardisorders. Betjes et al. (2008) Kidney International 74, 760-767 reportthat the increased risk for atherosclerotic disease in patients withCytomegalovirus (CMV) seropositivity is associated with age-dependentincrease of CD4⁺CD28⁻ T cells, which can comprise over half of thecirculating CD4 T cells in individuals. Patients over 50 years of agewere reported to have a 50-fold higher percentage of CD4⁺CD28⁻ T cellscompared to CMV seronegative patients and a 5-fold higher percentagewhen compared to seropositive healthy controls. Nakajima et al. ((2003)Circ. Res. 93:106-113) report de novo expression of KIR in acutecoronary syndrome, where CD4+ T cells from patients with acute coronarysyndrome (ACS) express multiple KIR whereas normal CD4+CD28null T cellsfrom healthy donors do not express KIR. Yen et al. Journal ofExperimental Medicine, Volume 193, Number 10, May 21, 2001 1159-1168studied CD4⁺CD28^(null) T cell clones established from patients withrheumatoid vasculitis for the expression of inhibitory and stimulatoryKIR by RT-PCR. In patients with rheumatoid arthritis and a patient withACS, the expression patterns favored the inhibitory KIR, includingKIR3DL2, whereas expression of stimulatory receptors was highlyrestricted to KIR2DS2. The methods and compositions of the invention cantherefore be used in the treatment or prevention of cardiovasculardisorders, e.g. ACS, atherosclerotic disease, rheumatoid vasculitis,characterized by inflammation.

The present invention provides novel methods for producing and usingantibodies and other compounds suitable for the treatment of disorders(e.g. cancers) where slowing the growth of and/or eliminatingKIR3DL2-expressing cells would be useful. Antibodies, antibodyderivatives, antibody fragments, and hybridomas are encompassed, as aremethods of producing the same and methods of treating patients using theantibodies and compounds.

Definitions

As used herein, “T” cells refers to a sub-population of lymphocytes thatmature in the thymus, and which display, among other molecules, T cellreceptors on their surface. T cells can be identified by virtue ofcertain characteristics and biological properties, such as theexpression of specific surface antigens including the TCR, CD4 or CD8,the ability of certain T cells to kill tumor or infected cells, theability of certain T cells to activate other cells of the immune system,and the ability to release protein molecules called cytokines thatstimulate or inhibit the immune response. Any of these characteristicsand activities can be used to identify T cells, using methods well knownin the art.

Within the context of this invention, “active” or “activated” T cellsdesignate biologically active T cells, more particularly T cells havingthe capacity of cytolysis or of stimulating an immune response by, e.g.,secreting cytokines. Active cells can be detected by any of a number ofwell known methods, including functional assays and expression-basedassays such as the expression of cytokines such as TNF-alpha.

Within the context of this invention a “common determinant” designates adeterminant or epitope that is shared by several gene products of thehuman inhibitory KIR3D receptors (e.g. shared by at least two KIR3Dreceptors, shared by all KIR3D receptors). More preferably, thedeterminant is shared by at least KIR3DL1 and KIR3DL2, and optionallyfurther by KIR3DS1. The determinant or epitope may represent a peptidefragment or a conformational epitope shared by said members. In a morespecific embodiment, the antibody of this invention specifically bindsto substantially the same epitope recognized by monoclonal antibodychAZ158. This determinant is present on KIR3DL1, KIR3DL2 and KIR3DS1.Within the context of this invention, the term antibody that “binds” acommon determinant designates an antibody that binds said determinantwith specificity and/or affinity.

KIR3DL2 (CD158k) is a disulphide-linked homodimer of three-Ig domainmolecules of about 140 kD, described in Pende et al. (1996) J. Exp. Med.184: 505-518, the disclosure of which is incorporated herein byreference. KIR3DL1 (CD158e1) is a monomeric molecule of about 70 kD,described in Colonna and Samaridis (1995) Science 268 (5209), 405-408.As used herein, “KIR3D” refers to any KIR3D receptor (e.g. KIR3DL1,KIR3DL2, KIR3DS1) individually or collectively, and the term “KIR3D” maybe substituted by the term “KIR3DL1, KIR3DL2 and/or KIR3DS1”. Similarly,“KIR3DL” refers to any KIR3DL receptor (e.g. KIR3DL1, KIR3DL2)individually or collectively, and the term “KIR3DL” may be substitutedby the term “KIR3DL1 and/or KIR3DL2”. The terms “KIR3D”, “KIR3DL”,“KIR3DL1”, “KIR3DL2”, “KIR3DS1” each furthermore include any variant,derivative, or isoform of the KIR3D gene or encoded protein(s) to whichthey refer. Several allelic variants have been reported for KIR3Dpolypeptides (e.g. KIR3DL2); each of these are encompassed by therespective terms. Sequences of human KIR3DL1 are also shown in SEQ IDNOS 1 and 2 for human cDNA and amino acid sequences, respectively,corresponding to Genbank accession nos. L41269 and AAA69870. Sequencesof human KIR3DL2 are also shown in SEQ ID NOS 3 and 4 for human cDNA andamino acid sequences, respectively, corresponding to Genbank accessionnos. L41270 and AAA69871. Sequences of human KIR3DS1 (CD158e2) are alsoshown in SEQ ID NOS 5 and 6 for human cDNA and amino acid sequences,respectively, corresponding to Genbank accession nos. L76661 andAAB36589. Also encompassed are any nucleic acid or protein sequencessharing one or more biological properties or functions with wild type,full length KIR3DL or KIR3DS, respectively, and sharing at least 70%,80%, 90%, 95%, 96%, 97%, 98%, 99%, or higher nucleotide or amino acididentity.

As used herein “KIR3DL signaling” or “KIR3DL2 signaling” refers to anability of a KIR3DL or KIR3DL2 polypeptide, respectively, to activate ortransduce an intracellular signaling pathway. Changes in KIR3DLsignaling activity can be measured, for example, by assays designed tomeasure changes in KIR3DL signaling pathways, e.g. by monitoringphosphorylation of signal transduction components such as SHP-1, assaysto measure the association of certain signal transduction componentswith other proteins or intracellular structures, or in the biochemicalactivity of components such as kinases, or assays designed to measureexpression of reporter genes under control of KIR3DL-sensitive promotersand enhancers, or indirectly by a downstream effect mediated by theKIR3DL polypeptide (e.g. inhibition of cell proliferation). Reportergenes can be naturally occurring genes (e.g. monitoring cytokineproduction) or they can be genes artificially introduced into a cell.Other genes can be placed under the control of such regulatory elementsand thus serve to report the level of KIR3DL signaling.

As used herein, the terms “stimulating” or “activating” with respect tothe effect of the herein-described compounds on KIR3DL refers to theability of the compounds to bind to KIR3DL (e.g. KIR3DL2) present on thesurface or in a cytoplasmic compartment of a cell, and to induce KIR3DL(e.g. KIR3DL2) signaling. Any detectable difference in KIR3DL signalingcan indicate that a compound stimulates or activates a KIR3DL receptor.Regardless of the assay used, an alteration of 10%, 20%, 30%, 40%, 50%,60%, 70%, 80%, 90%, 100%, 200%, 300%, 400%, 500%, 1000%, or more in anyaspect of KIR3DL signaling may be indicative of stimulation oractivation.

The term “depleting”, with respect to KIR3DL-expressing cells means aprocess, method, or compound that can kill, eliminate, lyse or inducesuch killing, elimination or lysis, so as to negatively affect thenumber of KIR3DL-expressing cells present in a sample or in a subject.

The term “antibody,” as used herein, refers to polyclonal and monoclonalantibodies. Depending on the type of constant domain in the heavychains, antibodies are assigned to one of five major classes: IgA, IgD,IgE, IgG, and IgM. Several of these are further divided into subclassesor isotypes, such as IgG1, IgG2, IgG3, IgG4, and the like. An exemplaryimmunoglobulin (antibody) structural unit comprises a tetramer. Eachtetramer is composed of two identical pairs of polypeptide chains, eachpair having one “light” (about 25 kDa) and one “heavy” chain (about50-70 kDa). The N-terminus of each chain defines a variable region ofabout 100 to 110 or more amino acids that is primarily responsible forantigen recognition. The terms variable light chain (V_(L)) and variableheavy chain (V_(H)) refer to these light and heavy chains respectively.The heavy-chain constant domains that correspond to the differentclasses of immunoglobulins are termed “alpha,” “delta,” “epsilon,”“gamma” and “mu,” respectively. The subunit structures andthree-dimensional configurations of different classes of immunoglobulinsare well known. IgG and/or IgM are the preferred classes of antibodiesemployed in this invention, with IgG being particularly preferred,because they are the most common antibodies in the physiologicalsituation and because they are most easily made in a laboratory setting.Preferably the antibody of this invention is a monoclonal antibody.Particularly preferred are humanized, chimeric, human, orotherwise-human-suitable antibodies. “Antibodies” also includes anyfragment or derivative of any of the herein described antibodies.

The term “specifically binds to” means that an antibody can bindpreferably in a competitive binding assay to the binding partner, e.g.KIR3DL2, as assessed using either recombinant forms of the proteins,epitopes therein, or native proteins present on the surface of isolatedT cells or other target cells. Competitive binding assays and othermethods for determining specific binding are further described below andare well known in the art.

When an antibody or agent is said to “compete” or “bind to substantiallythe same epitope” as a particular monoclonal antibody (e.g. the bivalentantibody comprising a heavy chain variable region comprising SEQ ID NO 8and a light chain variable region comprising SEQ ID NO 10), it meansthat the antibody or agent competes with the monoclonal antibody in abinding assay using either recombinant KIR3D (e.g. KIR3DL2) molecules orsurface expressed KIR3D (e.g. KIR3DL2) molecules. For example, if a testantibody or agent reduces the binding of a bivalent antibody comprisinga heavy chain variable region comprising SEQ ID NO 8 and a light chainvariable region comprising SEQ ID NO 10 to a KIR3D (e.g. KIR3DL2)polypeptide in a binding assay, the antibody or agent is said to“compete” with chAZ158, respectively.

By “immunogenic fragment,” it is herein meant any polypeptidic orpeptidic fragment that is capable of eliciting an immune response suchas (i) the generation of antibodies binding said fragment and/or bindingany form of the molecule comprising said fragment, including themembrane-bound receptor and mutants derived therefrom, (ii) thestimulation of a T-cell response involving T-cells reacting to thebi-molecular complex comprising any MHC molecule and a peptide derivedfrom said fragment, (iii) the binding of transfected vehicles such asbacteriophages or bacteria expressing genes encoding mammalianimmunoglobulins. Alternatively, an immunogenic fragment also refers toany construction capable of eliciting an immune response as definedabove, such as a peptidic fragment conjugated to a carrier protein bycovalent coupling, a chimeric recombinant polypeptide constructcomprising said peptidic fragment in its amino acid sequence, andspecifically includes cells transfected with a cDNA of which sequencecomprises a portion encoding said fragment.

“Toxic” or “cytotoxic” peptides or small molecules encompass anycompound that can slow down, halt, or reverse the proliferation ofcells, decrease their activity in any detectable way, or directly orindirectly kill them. Preferably, toxic or cytotoxic compounds work bydirectly killing the cells, by provoking ADCC or otherwise. As usedherein, a toxic “peptide” can include any peptide, polypeptide, orderivative of such, including peptide- or polypeptide-derivatives withunnatural amino acids or modified linkages. A toxic “small molecule” caninclude any toxic compound or element, preferably with a size of lessthan 10 kD, 5 kD, 1 kD, 750 D, 600 D, 500 D, 400 D, 300 D, or smaller.

A “human-suitable” antibody refers to any antibody, derivatizedantibody, or antibody fragment that can be safely used in humans for,e.g., the therapeutic methods described herein. Human-suitableantibodies include all types of humanized, chimeric, or fully humanantibodies, or any antibodies in which at least a portion of theantibodies is derived from humans or otherwise modified so as to avoidthe immune response that is generally provoked when native non-humanantibodies are used.

For the purposes of the present invention, a “humanized” or “human”antibody refers to an antibody in which the constant and variableframework region of one or more human immunoglobulins is fused with thebinding region, e.g. the CDR, of an animal immunoglobulin. Suchantibodies are designed to maintain the binding specificity of thenon-human antibody from which the binding regions are derived, but toavoid an immune reaction against the non-human antibody. Such antibodiescan be obtained from transgenic mice or other animals that have been“engineered” to produce specific human antibodies in response toantigenic challenge (see, e.g., Green et al. (1994) Nature Genet 7:13;Lonberg et al. (1994) Nature 368:856; Taylor et al. (1994) Int Immun6:579, the entire teachings of which are herein incorporated byreference). A fully human antibody also can be constructed by genetic orchromosomal transfection methods, as well as phage display technology,all of which are known in the art (see, e.g., McCafferty et al. (1990)Nature 348:552-553). Human antibodies may also be generated by in vitroactivated B cells (see, e.g., U.S. Pat. Nos. 5,567,610 and 5,229,275,which are incorporated in their entirety by reference).

A “chimeric antibody” is an antibody molecule in which (a) the constantregion, or a portion thereof, is altered, replaced or exchanged so thatthe antigen binding site (variable region) is linked to a constantregion of a different or altered class, effector function and/orspecies, or an entirely different molecule which confers new propertiesto the chimeric antibody, e.g., an enzyme, toxin, hormone, growthfactor, drug, etc.; or (b) the variable region, or a portion thereof, isaltered, replaced or exchanged with a variable region having a differentor altered antigen specificity.

The terms “isolated”, “purified” or “biologically pure” refer tomaterial that is substantially or essentially free from components whichnormally accompany it as found in its native state. Purity andhomogeneity are typically determined using analytical chemistrytechniques such as polyacrylamide gel electrophoresis or highperformance liquid chromatography. A protein that is the predominantspecies present in a preparation is substantially purified.

The term “biological sample” as used herein includes but is not limitedto a biological fluid (for example serum, lymph, blood), cell sample, ortissue sample (for example bone marrow or tissue biopsy includingmucosal tissue such as from the gut, gut lamina propria, or lungs).

The terms “polypeptide,” “peptide” and “protein” are usedinterchangeably herein to refer to a polymer of amino acid residues. Theterms apply to amino acid polymers in which one or more amino acidresidue is an artificial chemical mimetic of a corresponding naturallyoccurring amino acid, as well as to naturally occurring amino acidpolymers and non-naturally occurring amino acid polymers.

The term “recombinant” when used with reference, e.g., to a cell,nucleic acid, protein, or vector, indicates that the cell, nucleic acid,protein or vector has been modified by the introduction of aheterologous nucleic acid or protein or the alteration of a nativenucleic acid or protein, or that the cell is derived from a cell somodified. Thus, for example, recombinant cells express genes that arenot found within the native (nonrecombinant) form of the cell or expressnative genes that are otherwise abnormally expressed, underexpressed ornot expressed at all.

The terms “Fc domain”, “Fc portion”, “Fc tail” and “Fc region” refer toa C-terminal fragment of an antibody heavy chain, e.g., from about aminoacid (aa) 230 to about aa 450 of human γ (gamma) heavy chain or itscounterpart sequence in other types of antibody heavy chains (e.g., α,δ, ε and μ for human antibodies), or a naturally occurring allotypethereof. Unless otherwise specified, the commonly accepted Kabat aminoacid numbering for immunoglobulins is used throughout this disclosure(see Kabat et al. (1991) Sequences of Protein of Immunological Interest,5th ed., United States Public Health Service, National Institute ofHealth, Bethesda, Md.).

The term “antibody-dependent cell-mediated cytotoxicity” or “ADCC” is aterm well understood in the art, and refers to a cell-mediated reactionin which non-specific cytotoxic cells that express Fc receptors (FcRs)recognize bound antibody on a target cell and subsequently cause lysisof the target cell. Non-specific cytotoxic cells that mediate ADCCinclude natural killer (NK) cells, macrophages, monocytes, neutrophils,and eosinophils.

“Autoimmune” disorders include any disorder, condition, or disease inwhich the immune system mounts a reaction against self cells or tissues,due to a breakdown in the ability to distinguish self from non-self orotherwise. Examples of autoimmune disorders include rheumatoidarthritis, rheumatoid vascularitis, systemic lupus erythematosus,multiple sclerosis, Wegener's granulomatosis, spondylarthritis, andothers. An “inflammatory disorder” includes any disorder characterizedby an unwanted immune response. Autoimmune and inflammatory disorderscan involve any component of the immune system, and can target any cellor tissue type in the body.

Producing Anti-KIR3DL2 Antibodies

The antibodies of this invention specifically bind to KIR3DL2polypeptides, e.g., KIR3DL2 polypeptides on the surface of human cells.The ability of the antibodies to bind KIR3DL2 polypeptides makes themuseful for numerous applications, e.g., purifying human or other primatecells, or specifically labeling human or other primate cells in vitro,in vivo, or ex vivo. The ability to specifically purify and label cellsis useful for, inter alia, diagnostic purposes (e.g. to detect humanmalignant CD4+ T cells involved in autoimmune or inflammatory disorderssuch as arthritis and cardiovascular disease). In certain embodiments,the antibodies also specifically bind to KIR3DL1 and/or KIR3DS1polypeptides in addition to KIR3DL2, e.g., KIR3DL1 and/or KIR3DS1polypeptides on the surface of human cells. Preferably the antibodiescomprise a constant region capable of crosslinking receptors (e.g.antibody having a constant region of human IgG1 subtype, or othersubtype having the ability to bind Fc receptors). Such antibodies canreadily be modified so as to have properties of depletingKIR3DL-expressing cells, particularly via ADCC. The antibodies can beprepared so as to have an Fc portion that binds CD16 and induces ADCC.Optionally the Fc region is modified (e.g. glycosylation modified,hypofucosylated, comprising amino acid modifications, etc.) so as tohave increased ADCC activity compared to a reference Fc portion.

As such, the present antibodies are useful for, inter alia, treating orpreventing disorders characterized by a pathogenic expansion ofKIR3D-expressing cells, e.g., conditions resulting from an increase inthe number or activity of KIR3D-expressing cells, or conditions that canbe prevented or ameliorated by decreasing the number or activity ofKIR3DL-expressing cells.

In a preferred embodiment, the invention provides an antibody that bindsa human KIR3DL2 dimer, modulates the activity or proliferation of Tcells, and competes with monoclonal antibody chAZ158 for binding tohuman KIR3DL2. Optionally, said antibody is a chimeric, human, orhumanized antibody. Depending on the antibodies or particular derivativeor fragment used, the antibodies of the invention can either increase ordecrease the activity of T cells.

In an advantageous aspect, the invention provides an antibody thatcompetes with the bivalent antibody comprising a heavy chain variableregion comprising SEQ ID NO 8 and a light chain variable regioncomprising SEQ ID NO 10 and recognizes, binds to, or hasimmunospecificity for substantially or essentially the same, or thesame, epitope or “epitopic site” on a KIR3DL2, KIR3DL1 and/or KIR3DS1molecule. In other embodiments, the monoclonal antibody consists of, oris a derivative or fragment thereof.

The antibodies of this invention may be produced by a variety oftechniques known in the art. Typically, they are produced byimmunization of a non-human animal, preferably a mouse, with animmunogen comprising a KIR3DL polypeptide, preferably a cell expressingat its surface a human KIR3DL2 dimer. The KIR3DL polypeptide maycomprise the full length sequence of a human KIR3DL polypeptide, or afragment or derivative thereof, typically an immunogenic fragment, i.e.,a portion of the polypeptide comprising an epitope exposed on thesurface of cells expressing a KIR3DL polypeptide. Such fragmentstypically contain at least about 7 consecutive amino acids of the maturepolypeptide sequence, even more preferably at least about 10 consecutiveamino acids thereof. Fragments typically are essentially derived fromthe extra-cellular domain of the receptor. In a preferred embodiment,the immunogen comprises a wild-type human KIR3DL2 polypeptide in a lipidmembrane, typically at the surface of a cell. In a specific embodiment,the immunogen comprises intact SS or MF cells, particularly intact humanmalignant CD4+ T cells, or CD4+CD28− T cells, optionally treated orlysed. In another preferred embodiment, the polypeptide is a recombinantdimeric KIR3DL2 polypeptide.

The step of immunizing a non-human mammal with an antigen may be carriedout in any manner well known in the art for stimulating the productionof antibodies in a mouse (see, for example, E. Harlow and D. Lane,Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory Press,Cold Spring Harbor, N.Y. (1988), the entire disclosure of which isherein incorporated by reference). The immunogen is suspended ordissolved in a buffer, optionally with an adjuvant, such as completeFreund's adjuvant. Methods for determining the amount of immunogen,types of buffers and amounts of adjuvant are well known to those ofskill in the art and are not limiting in any way on the presentinvention. These parameters may be different for different immunogens,but are easily elucidated.

Similarly, the location and frequency of immunization sufficient tostimulate the production of antibodies is also well known in the art. Ina typical immunization protocol, the non-human animals are injectedintraperitoneally with antigen on day 1 and again about a week later.This is followed by recall injections of the antigen around day 20,optionally with adjuvant such as incomplete Freund's adjuvant. Therecall injections are performed intravenously and may be repeated forseveral consecutive days. This is followed by a booster injection at day40, either intravenously or intraperitoneally, typically withoutadjuvant. This protocol results in the production of antigen-specificantibody-producing B cells after about 40 days. Other protocols may alsobe utilized as long as they result in the production of B cellsexpressing an antibody directed to the antigen used in immunization.

For polyclonal antibody preparation, serum is obtained from an immunizednon-human animal and the antibodies present therein isolated bywell-known techniques. The serum may be affinity purified using any ofthe immunogens set forth above linked to a solid support so as to obtainantibodies that react with KIR3DL2 polypeptides.

In an alternate embodiment, lymphocytes from an unimmunized non-humanmammal are isolated, grown in vitro, and then exposed to the immunogenin cell culture. The lymphocytes are then harvested and the fusion stepdescribed below is carried out.

For monoclonal antibodies, the next step is the isolation of splenocytesfrom the immunized non-human mammal and the subsequent fusion of thosesplenocytes with an immortalized cell in order to form anantibody-producing hybridoma. The isolation of splenocytes from anon-human mammal is well-known in the art and typically involvesremoving the spleen from an anesthetized non-human mammal, cutting itinto small pieces and squeezing the splenocytes from the splenic capsuleand through a nylon mesh of a cell strainer into an appropriate bufferso as to produce a single cell suspension. The cells are washed,centrifuged and resuspended in a buffer that lyses any red blood cells.The solution is again centrifuged and remaining lymphocytes in thepellet are finally resuspended in fresh buffer.

Once isolated and present in single cell suspension, the lymphocytes canbe fused to an immortal cell line. This is typically a mouse myelomacell line, although many other immortal cell lines useful for creatinghybridomas are known in the art. Preferred murine myeloma lines include,but are not limited to, those derived from MOPC-21 and MPC-11 mousetumors available from the Salk Institute Cell Distribution Center, SanDiego, U.S.A, X63 Ag8653 and SP-2 cells available from the American TypeCulture Collection, Rockville, Md. U.S.A. The fusion is effected usingpolyethylene glycol or the like. The resulting hybridomas are then grownin selective media that contains one or more substances that inhibit thegrowth or survival of the unfused, parental myeloma cells. For example,if the parental myeloma cells lack the enzyme hypoxanthine guaninephosphoribosyl transferase (HGPRT or HPRT), the culture medium for thehybridomas typically will include hypoxanthine, aminopterin, andthymidine (HAT medium), which substances prevent the growth ofHGPRT-deficient cells.

Hybridomas are typically grown on a feeder layer of macrophages. Themacrophages are preferably from littermates of the non-human mammal usedto isolate splenocytes and are typically primed with incomplete Freund'sadjuvant or the like several days before plating the hybridomas. Fusionmethods are described in Goding, “Monoclonal Antibodies: Principles andPractice,” pp. 59-103 (Academic Press, 1986), the disclosure of which isherein incorporated by reference.

The cells are allowed to grow in the selection media for sufficient timefor colony formation and antibody production. This is usually betweenabout 7 and about 14 days.

The hybridoma colonies are then assayed for the production of antibodiesthat specifically bind to KIR3DL polypeptides. The assay is typically acolorimetric ELISA-type assay, although any assay may be employed thatcan be adapted to the wells that the hybridomas are grown in. Otherassays include radioimmunoassay. The wells positive for the desiredantibody production are examined to determine if one or more distinctcolonies are present. If more than one colony is present, the cells maybe re-cloned and grown to ensure that only a single cell has given riseto the colony producing the desired antibody.

Hybridomas that are confirmed to produce a monoclonal antibody of thisinvention can be grown in larger amounts in an appropriate medium, suchas DMEM or RPMI-1640. Alternatively, the hybridoma cells can be grown invivo as ascites tumors in an animal.

After sufficient growth to produce the desired monoclonal antibody, thegrowth media containing monoclonal antibody (or the ascites fluid) isseparated away from the cells and the monoclonal antibody presenttherein is purified. Purification is typically achieved by gelelectrophoresis, dialysis, chromatography using protein A or proteinG-Sepharose, or an anti-mouse Ig linked to a solid support such asagarose or Sepharose beads (all described, for example, in the AntibodyPurification Handbook, Biosciences, publication No. 18-1037-46, EditionAC, the disclosure of which is hereby incorporated by reference). Thebound antibody is typically eluted from protein A/protein G columns byusing low pH buffers (glycine or acetate buffers of pH 3.0 or less) withimmediate neutralization of antibody-containing fractions. Thesefractions are pooled, dialyzed, and concentrated as needed.

Positive wells with a single apparent colony are typically re-cloned andre-assayed to ensure only one monoclonal antibody is being detected andproduced.

Antibodies may also be produced by selection of combinatorial librariesof immunoglobulins, as disclosed for instance in Ward et al., Nature,341 (1989) p. 544, the entire disclosure of which is herein incorporatedby reference.

The identification of one or more antibodies that bind(s) tosubstantially or essentially the same epitope as the anti-KIR3DL2monoclonal antibodies described herein can be readily determined usingany one of a variety of immunological screening assays in which antibodycompetition can be assessed. A number of such assays are routinelypracticed and well known in the art (see, e. g. U.S. Pat. No. 5,660,827,issued Aug. 26, 1997, which is specifically incorporated herein byreference). It will be understood that actually determining the epitopeto which an antibody described herein binds is not in any way requiredto identify an antibody that binds to the same or substantially the sameepitope as the monoclonal antibody described herein.

For example, where the test antibodies to be examined are obtained fromdifferent source animals, or are even of a different Ig isotype, asimple competition assay may be employed in which the control (forexample chAZ158, which is a bivalent antibody comprising a heavy chainvariable region comprising SEQ ID NO 8 and a light chain variable regioncomprising SEQ ID NO 10) and test antibodies are admixed (orpre-adsorbed) and applied to a sample containing KIR3DL polypeptides.Protocols based upon Western blotting and the use of BIACORE analysisare suitable for use in such simple competition studies.

In certain embodiments, one pre-mixes the control antibodies (chAZ158,for example) with varying amounts of the test antibodies (e.g., about1:10 or about 1:100) for a period of time prior to applying to theKIR3DL2 antigen sample. In other embodiments, the control and varyingamounts of test antibodies can simply be admixed during exposure to theKIR3DL2 antigen sample. As long as one can distinguish bound from freeantibodies (e. g. by using separation or washing techniques to eliminateunbound antibodies) and chAZ158 from the test antibodies (e. g., byusing species-specific or isotype-specific secondary antibodies or byspecifically labeling chAZ158 with a detectable label) one can determineif the test antibodies reduce the binding of chAZ158 to the antigens,indicating that the test antibody recognizes substantially the sameepitope as chAZ158. The binding of the (labeled) control antibodies inthe absence of a completely irrelevant antibody can serve as the controlhigh value. The control low value can be obtained by incubating thelabeled (chAZ158) antibodies with unlabelled antibodies of exactly thesame type (chAZ158), where competition would occur and reduce binding ofthe labeled antibodies. In a test assay, a significant reduction inlabeled antibody reactivity in the presence of a test antibody isindicative of a test antibody that recognizes substantially the sameepitope. Any test antibody that reduces the binding of chAZ158 toKIR3DL2 antigens by at least about 50%, such as at least about 60%, ormore preferably at least about 70% (e. g., about 65-100%), at any ratioof chAZ158:test antibody between about 1:10 and about 1:100 isconsidered to be an antibody that binds to substantially the sameepitope or determinant as chAZ158. Preferably, such test antibody willreduce the binding of chAZ158 to the KIR3DL2 antigen by at least about90% (e.g., about 95%).

Competition can be assessed by, for example, a flow cytometry test. Insuch a test, cells bearing a KIR3DL2 polypeptide can be incubated firstwith chAZ158, for example, and then with the test antibody labeled witha fluorochrome or biotin. The test antibody can be assessed in the sameway for competition chAZ158 for KIR3DL1 and KIR3DS1. The antibody issaid to compete with chAZ158 if the binding obtained upon preincubationwith a saturating amount of chAZ158 is about 80%, preferably about 50%,about 40% or less (e.g., about 30%) of the binding (as measured by meansof fluorescence) obtained by the antibody without preincubation withchAZ158. Alternatively, an antibody is said to compete with chAZ158 ifthe binding obtained with a labeled chAZ158 antibody (by a fluorochromeor biotin) on cells preincubated with a saturating amount of testantibody is about 80%, preferably about 50%, about 40%, or less (e. g.,about 30%) of the binding obtained without preincubation with theantibody.

A simple competition assay in which a test antibody is pre-adsorbed andapplied at saturating concentration to a surface onto which a KIR3DL2antigen is immobilized may also be employed. The surface in the simplecompetition assay is preferably a BIACORE chip (or other media suitablefor surface plasmon resonance analysis). The control antibody (e.g.,chAZ158) is then brought into contact with the surface at aKIR3DL2-saturating concentration and the KIR3DL2 and surface binding ofthe control antibody is measured. This binding of the control antibodyis compared with the binding of the control antibody to theKIR3DL2-containing surface in the absence of test antibody. In a testassay, a significant reduction in binding of the KIR3DL2-containingsurface by the control antibody in the presence of a test antibodyindicates that the test antibody recognizes substantially the sameepitope as the control antibody. Any test antibody that reduces thebinding of control (such as chAZ158) antibody to a KIR3DL2 antigen by atleast about 30% or more, preferably about 40%, can be considered to bean antibody that binds to substantially the same epitope or determinantas a control (e.g., chAZ158). Preferably, such a test antibody willreduce the binding of the control antibody (e.g., chAZ158) to theKIR3DL2 antigen by at least about 50% (e.g., at least about 60%, atleast about 70%, or more). It will be appreciated that the order ofcontrol and test antibodies can be reversed: that is, the controlantibody can be first bound to the surface and the test antibody isbrought into contact with the surface thereafter in a competition assay.Preferably, the antibody having higher affinity for the KIR3DL2 antigenis bound to the surface first, as it will be expected that the decreasein binding seen for the second antibody (assuming the antibodies arecross-reacting) will be of greater magnitude. Further examples of suchassays are provided in, e. g., Saunal (1995) J. Immunol. Methods 183:33-41, the disclosure of which is incorporated herein by reference.

Preferably, monoclonal antibodies that recognize a KIR3DL2 epitope willreact with an epitope that is present on a substantial percentage of oreven all relevant cells, e.g. malignant CD4+ T cells, cells from an SSor MF patient, but will not significantly react with other cells, i.e.,immune or non-immune cells that do not express KIR3DL2. In one aspect,the anti-KIR3DL2 antibodies of the invention bind KIR3DL2 but do notbind KIR3DL1 and/or KIR3DS1. In another aspect, monoclonal antibodiesthat recognize a KIR3DL2 epitope bind a common determinant present onKIR3DL1 and KIR3DL2, and optionally further a common determinant presenton KIR3DS1.

In preferred embodiments, the antibodies will bind to KIR3DL2-expressingcells from an individual or individuals with a disease characterized byexpression of KIR3DL2-positive cells, i.e. an individual that is acandidate for treatment with one of the herein-described methods usingan anti-KIR3DL2 antibody of the invention. Accordingly, once an antibodythat specifically recognizes KIR3DL2 on cells is obtained, it can betested for its ability to bind to KIR3DL2-positive cells (e.g. malignantCD4+ T cells) taken from a patient with a disorder such as SS or MF. Inparticular, prior to treating a patient with one of the presentantibodies, it will be beneficial to test the ability of the antibody tobind malignant cells taken from the patient, e.g. in a blood sample, tomaximize the likelihood that the therapy will be beneficial to thepatient.

In one embodiment, the antibodies of the invention are validated in animmunoassay to test their ability to bind to KIR3DL2-expressing cells,e.g. malignant CD4+ T cells, pro-inflammatory CD4+ cells. For example,peripheral blood lymphocytes (PBLs) are taken from a plurality ofpatients, and CD4+ T cells are enriched from the PBLs, e.g., by flowcytometry using relevant antibodies (for malignant CD4+ cells see, e.g.,Bagot et al. (2001) Blood 97:1388-1391, the disclosure of which isincorporated herein by reference), or CD4+CD28− cell fractions areisolated by magnetic separation on a MACS column (Miltenyi Biotec). Theability of a given antibody to bind to the cells is then assessed usingstandard methods well known to those in the art. Antibodies that arefound to bind to a substantial proportion (e.g., 20%, 30%, 40%, 50%,60%, 70%, 80% or more) of cells known to express KIR3DL2, e.g. T cells,from a significant percentage of individuals or patients (e.g., 5%, 10%,20%, 30%, 40%, 50% or more) are suitable for use in the presentinvention, both for diagnostic purposes to determine the presence orlevel of malignant T cells in a patient or for use in theherein-described therapeutic methods, e.g., for use to increase ordecrease malignant T cell numbers or activity. To assess the binding ofthe antibodies to the cells, the antibodies can either be directly orindirectly labeled. When indirectly labeled, a secondary, labeledantibody is typically added. The binding of the antibodies to the cellscan then be detected using, e.g., cytofluorometric analysis (e.g.FACScan). Such methods are well known to those of skill in the art.

While described in the context of chAZ158 for the purposes ofexemplification, it will be appreciated that the herein-describedimmunological screening assays and other assays can also be used toidentify antibodies that compete with other anti-KIR3DL2 antibodies, andother antibodies described herein or obtained according to the teachingsof the present specification.

Determination of whether an antibody binds within one of the epitoperegions defined above can be carried out in ways known to the personskilled in the art. As one example of such mapping/characterizationmethods, an epitope region for an anti-KIR3DL2 antibody may bedetermined by epitope “foot-printing” using chemical modification of theexposed amines/carboxyls in the KIR3DL2 protein. One specific example ofsuch a foot-printing technique is the use of HXMS (hydrogen-deuteriumexchange detected by mass spectrometry) wherein a hydrogen/deuteriumexchange of receptor and ligand protein amide protons, binding, and backexchange occurs, wherein the backbone amide groups participating inprotein binding are protected from back exchange and therefore willremain deuterated. Relevant regions can be identified at this point bypeptic proteolysis, fast microbore high-performance liquidchromatography separation, and/or electrospray ionization massspectrometry. See, e. g., Ehring H, Analytical Biochemistry, Vol. 267(2) pp. 252-259 (1999), Engen, J. R. and Smith, D. L. (2001) Anal. Chem.73, 256A-265A. Another example of a suitable epitope identificationtechnique is nuclear magnetic resonance epitope mapping (NMR), wheretypically the position of the signals in two-dimensional NMR spectra ofthe free antigen and the antigen complexed with the antigen bindingpeptide, such as an antibody, are compared. The antigen typically isselectively isotopically labeled with 15N so that only signalscorresponding to the antigen and no signals from the antigen bindingpeptide are seen in the NMR spectrum. Antigen signals originating fromamino acids involved in the interaction with the antigen binding peptidetypically will shift position in the spectrum of the complex compared tothe spectrum of the free antigen, and the amino acids involved in thebinding can be identified that way. See, e. g., Ernst, Schering ResFound Workshop, 2004; (44): 149-67; Huang et al. Journal of MolecularBiology, Vol. 281 (1) pp. 61-67 (1998); and Saito and Patterson,Methods, 1996 June; 9 (3): 516-24.

Epitope mapping/characterization also can be performed using massspectrometry methods. See, e.g., Downard, J Mass Spectrom. 2000 April;35 (4): 493-503 and Kiselar and Downard, Anal Chem. 1999 May 1; 71 (9):1792-801. Protease digestion techniques also can be useful in thecontext of epitope mapping and identification. Antigenicdeterminant-relevant regions/sequences can be determined by proteasedigestion, e. g. by using trypsin in a ratio of about 1:50 to KIR3DL2 oro/n digestion at pH 7-8, followed by mass spectrometry (MS) analysis forpeptide identification. The peptides protected from trypsin cleavage bythe anti-KIR3DL2 binder can subsequently be identified by comparison ofsamples subjected to trypsin digestion and samples incubated withantibody and then subjected to digestion by e. g. trypsin (therebyrevealing a footprint for the binder). Other enzymes like chymotrypsin,pepsin, etc. also or alternatively can be used in similar epitopecharacterization methods. Moreover, enzymatic digestion can provide aquick method for analyzing whether a potential antigenic determinantsequence is within a region of the KIR3DL2 polypeptide that is notsurface exposed and, accordingly, most likely not relevant in terms ofimmunogenicity/antigenicity.

Upon immunization and production of antibodies in a vertebrate or cell,particular selection steps may be performed to isolate antibodies asclaimed. In this regard, in a specific embodiment, the invention alsorelates to methods of producing such antibodies, comprising: (a)immunizing a non-human mammal with an immunogen comprising a KIR3DL2polypeptide; and (b) preparing antibodies from said immunized animal,wherein said antibodies bind said KIR3DL2 polypeptide. In oneembodiment, the method further comprises step (c), selecting antibodiesof (b) that are capable of depleting or inhibiting the proliferation ofKIR3DL2-expressing cells, or that activate KIR3DL2 (e.g. induce receptorsignaling).

In preferred embodiments, the antibodies prepared according to thepresent methods are monoclonal antibodies. In preferred embodiments, thenon-human animal used to produce antibodies according to the methods ofthe invention is a mammal, such as a rodent, bovine, porcine, horse,rabbit, goat, or sheep.

According to an alternate embodiment, the DNA encoding an antibody thatbinds an epitope present on KIR3DL2 polypeptides is isolated from thehybridoma of this invention and placed in an appropriate expressionvector for transfection into an appropriate host. The host is then usedfor the recombinant production of the antibody, or variants thereof,such as a humanized version of that monoclonal antibody, activefragments of the antibody, or chimeric antibodies comprising the antigenrecognition portion of the antibody.

DNA encoding the monoclonal antibodies can be readily isolated andsequenced using conventional procedures (e.g., by using oligonucleotideprobes that are capable of binding specifically to genes encoding theheavy and light chains of murine antibodies). Once isolated, the DNA canbe placed into expression vectors, which are then transfected into hostcells such as E. coli cells, simian COS cells, Chinese hamster ovary(CHO) cells, or myeloma cells that do not otherwise produceimmunoglobulin protein, to obtain the synthesis of monoclonal antibodiesin the recombinant host cells. As described elsewhere in the presentspecification, preferred host cells include avian host cells, as well asany other cells capable of producing hypofucosylated antibodies. The DNAsequences described herein can be modified for any of a large number ofpurposes, e.g., for humanizing antibodies, producing fragments orderivatives, or for modifying the sequence of the antibody, e.g., in theantigen binding site in order to optimize the binding specificity of theantibody.

Recombinant expression in bacteria of DNA encoding the antibody is wellknown in the art (see, for example, Skerra et al., Curr. Opinion inImmunol., 5, pp. 256 (1993); and Pluckthun, Immunol. 130, pp. 151(1992)). The invention therefore provides a host cell capable ofexpressing an antibody that binds an epitope present on KIR3DL2polypeptides, including but not limited to a recombinant host cell whichhas been transformed with a nucleic acid encoding an antibody that bindsan epitope present on a KIR3DL2 polypeptide.

Testing the Compounds for Activity

Once an antigen-binding compound is obtained it will generally beassessed for its ability to interact with, affect the activity of,and/or induce ADCC towards and/or inhibit the proliferation of targetcells or activate KIR3DL2 (e.g. induce receptor signaling). Assessingthe antigen-binding compound's ability to induce ADCC or activateKIR3DL2, whether directly by monitoring signal transduction pathways orindirectly by monitoring inhibition of the proliferation of targetcells, can be carried out at any suitable stage of the method, andexamples are provided herein. This assessment can be useful at one ormore of the various steps involved in the identification, productionand/or development of an antibody (or other compound) destined fortherapeutic use. For example, ADCC, receptor signaling or anti-cellproliferation activity may be assessed in the context of a screeningmethod to identify candidate antigen-binding compounds, or in methodswhere an antigen-binding compound is selected and made human suitable(e.g. made chimeric or humanized in the case of an antibody), where acell expressing the antigen-binding compound (e.g. a host cellexpressing a recombinant antigen-binding compound) has been obtained andis assessed for its ability to produce functional antibodies (or othercompounds), and/or where a quantity of antigen-binding compound has beenproduced and is to be assessed for activity (e.g. to test batches orlots of product). Generally the antigen-binding compound will be knownto specifically bind to a KIR3DL2 polypeptide. The step may involvetesting a plurality (e.g., a very large number using high throughputscreening methods or a smaller number) of antigen-binding compounds fortheir ADCC induction or anti-cell proliferation activity, or testing asingle compound.

Typically, analysis of the anti-KIR3DL2 antibody's activity inactivating KIR3DL2 by monitoring signal transduction, e.g. theinhibitory signalling cascade, involves monitoring KIR3DL2-inducedphosphorylation patterns. Preferably, phosphorylation of moleculesimplicated in KIR inhibitory signalling such as SHP-1 is followed. Uponsignalling, SHP-1 appears phosphorylated upon KIR3DL2 engagement as ithas been previously shown for other inhibitory receptors (Vely F. (1997)Eur. J. Immunol. 27(8): 1994-2000; Yusa S. (2002) J. Immun.168(10):5047-57; Long E. O. (2001) Immunol. Rev. 181:223-33; andCarretero M. (1998) Eur. J. Immunol. 28(4):1280-91). The experiment iscarried out with an anti-KIR3DL2 antibody (e.g. chAZ158) binding toKIR3DL2 with different cell lines or freshly sorted human cells. Eachthese references for assays are herein incorporated by reference intheir entirety.

Other preferred assays include indirect approaches to detect KIR3DL2receptor signalling. In one example, the effect of chAZ158 antibody onthe inhibition of phosphorylation of molecules implicated in theactivation cascade under TCR/CD3 activation is evaluated. Many moleculessuch as SLP-76, LAT, vav-1 or ZAP-70 are implicated in the TCR/CD3activating pathway (Leo A. (2001) Current Opinions Immunol.13(3):307-16; Horejsi V. (2004) Nature Reviews 4(8):603-16). The AZ158chimeric antibody can also be assessed for its ability to inhibit theproliferation of cells previously activated by anti-CD3 antibodies, bymonitoring a decrease in the phosphorylation of key molecules implicatedin the TCR/CD3 activation pathway. These biochemical experiments areperformed in the presence or not of the anti-KIR3DL2 antibody (e.g.chAZ158) as previously described for different membrane receptors (ChenX. (2007) PNAS 104(15):6329-34; Fourmentraux-Neves E. (2008) Blood112(6):2381-9; Nikolova M. (2002) Blood 100(3):1019-25; Stebbins C.(2003) Mol Cell Biol. 23(17):6291-9). The localization of the differentmolecules implicated in the KIR3DL2 inhibitory cascade or in the TCR/CD3signalisation cascade are monitored by confocal microscopy (Liu Y.(2007) J. Leukocyte Biology 82: 742-751; Fourmentraux-Neves E. (2008)).This is done by incubating cell lines or freshly sorted human cells withfree AZ158 antibodies or AZ158 coated beads to create a synapticplatform. Another indirect approach involves monitoring cellular effectsof signalling, including cytokine production, cell proliferation orgrowth, markers of cytoxicity, etc. Each these references for assays areherein incorporated by reference in their entirety.

Examples of assays for assessing KIR3DL2 signalling include the assaysdescribed herein in Example 5; cells expressing KIR3DL2, optionallyfurther not expressing other KIR3D polypeptides (e.g. Sézary Syndromecells which express KIR3DL2 but not other KIRs), are brought intocontact with an anti-KIR3DL2 antibody (e.g. chAZ158 antibody) in theabsence of effector cells, and the cells' proliferation is assessed.Optionally cells express KIR3DL2 and additionally other KIR3D receptorsto which an anti-KIR3D antibody binds. To measure cell proliferation orgrowth, any suitable method such as determining cell number or density,including the methods used in the Example 5 section herein(CellTiter-Glo Luminescent Cell Viability Assay, Promega) or determiningthe mitotic index, or any other method to determine the number of cellsor their position in the cell cycle can be used. In vivo assays can beused as well, e.g. administering the antibodies to animal models, e.g.,mice, containing target cells, and detecting the effect of the antibodyadministration on the survival, growth or activity of the target cellsover time. In certain embodiments, an assay comprises detectinginhibition of cell proliferation in the absence of effector (e.g. NK)cells, where the antibody is capable of producing a decrease of at least10%, 20%, 30%, 40%, or 50% in the number of target cells or compared totarget cells incubated in the absence of antibody. Target cells may be,for example, KIR3DL2-expressing cells, e.g. CD4+ T cells, Cou-L cells ormalignant T cells from an SS or MF patient, or CD4+CD28− T cells.

Testing antibody-dependent cellular cytotoxicity (ADCC) typicallyinvolves assessing cell-mediated cytotoxicity in which aKIR3DL-expressing target cell (e.g. a Cou-L cell, Sézary Syndrome cellor other KIR3DL-expressing cell) with bound anti-KIR3DL2 antibody isrecognized by an effector cell bearing Fc receptors, without theinvolvement of complement. A cell which does not express a KIR3DLantigen can optionally be used as a control. Several exemplary ADCCassays are described in Example 5 herein. Activation of NK cellcytotoxicity is assessed by measuring an increase in cytokine production(e.g. IFN-γ production) or cytotoxicity markers (e.g. CD107mobilization). Preferably the antibody of the invention will induce anincrease in cytokine production, expression of cytoxicity markers, ortarget cell lysis of at least 20%, 50%, 80%, 100%, 200% or 500% in thepresence of target cells, compared to a control antibody (e.g. anantibody not binding to KIR3DL, a KIR3DL2 antibody having murineconstant regions, a KIR3DL2 antibody produced in CHO cells and nothypofucosylated, etc.). In another example, lysis of target cells isdetected, e.g. in a chromium release assay; preferably the antibody ofthe invention will induce lysis of at least 10%, 20%, 30%, 40% or 50% oftarget cells. Where an antigen-binding compound is tested for both itsability to (a) induce ADCC and (b) induce KIR3DL2 activation (receptorsignaling), the assays of (a) and (b) can be carried out in any order.

Fragments and Derivatives of the Present Monoclonal Antibodies

Fragments and derivatives of antibodies of this invention (which areencompassed by the term “antibody” or “antibodies” as used in thisapplication, unless otherwise stated or clearly contradicted bycontext), preferably a chAZ158-like antibody, can be produced bytechniques that are known in the art. “Fragments” comprise a portion ofthe intact antibody, generally the antigen binding site or variableregion. Examples of antibody fragments include Fab, Fab′, F(ab)₂,F(ab′)₂, F(ab)₃, Fv (typically the VL and VH domains of a single arm ofan antibody), single-chain Fv (scFv), dsFv, Fd (typically the VH and CH1domain), and dAb (typically a VH domain) fragments; VH, VL, VhH, andV-NAR domains; minibodies, diabodies, triabodies, tetrabodies, and kappabodies (see, e.g., Ill et al., Protein Eng 1997; 10: 949-57); camel IgG;IgNAR; and multispecific antibody fragments formed from antibodyfragments, and one or more isolated CDRs or a functional paratope, whereisolated CDRs or antigen-binding residues or polypeptides can beassociated or linked together so as to form a functional antibodyfragment. Examples of preferred antibody fragments also include anyantibody fragment that is a polypeptide having a primary structureconsisting of one uninterrupted sequence of contiguous amino acidresidues (referred to herein as a “single-chain antibody fragment” or“single chain polypeptide”), including without limitation (1)single-chain Fv molecules, (2) single chain polypeptides containing onlyone light chain variable domain, or a fragment thereof that contains thethree CDRs of the light chain variable domain, without an associatedheavy chain moiety and (3) single chain polypeptides containing only oneheavy chain variable region, or a fragment thereof containing the threeCDRs of the heavy chain variable region, without an associated lightchain moiety; and multispecific antibodies formed from antibodyfragments. Various types of antibody fragments have been described orreviewed in, e.g., Holliger and Hudson (2005) Nat Biotech. 23:1126-1136; WO2005040219; and published U.S. Patent Applications20050238646 and 20020161201.

Fragments of the present antibodies can be obtained using standardmethods. For instance, Fab or F(ab′)₂ fragments may be produced byprotease digestion of the isolated antibodies, according to conventionaltechniques. It will be appreciated that immunoreactive fragments can bemodified using known methods, for example to slow clearance in vivo andobtain a more desirable pharmacokinetic profile the fragment may bemodified with polyethylene glycol (PEG). Methods for coupling andsite-specifically conjugating PEG to a Fab′ fragment are described in,for example, Leong et al, 16 (3): 106-119 (2001) and Delgado et al, Br.J. Cancer 73 (2): 175-182 (1996), the disclosures of which areincorporated herein by reference.

Alternatively, the DNA of a hybridoma producing an antibody of thisinvention may be modified so as to encode a fragment of this invention.The modified DNA is then inserted into an expression vector and used totransform or transfect an appropriate cell, which then expresses thedesired fragment.

In certain embodiments, the DNA of a hybridoma producing an antibody ofthis invention can be modified prior to insertion into an expressionvector, for example, by substituting the coding sequence for humanheavy- and light-chain constant domains in place of the homologousnon-human sequences (e.g., Morrison et al., Proc. Natl. Acad. Sci. U. S.pp. 6851 (1984), or by covalently joining to the immunoglobulin codingsequence all or part of the coding sequence for a non-immunoglobulinpolypeptide. In that manner, “chimeric” or “hybrid” antibodies areprepared that have the binding specificity of the original antibody.Typically, such non-immunoglobulin polypeptides are substituted for theconstant domains of an antibody of the invention.

In one particularly preferred embodiment, the antibodies of thisinvention are humanized. “Humanized” forms of antibodies according tothis invention are specific chimeric immunoglobulins, immunoglobulinchains or fragments thereof (such as Fv, Fab, Fab′, F(ab′)₂, or otherantigen-binding subsequences of antibodies) which contain minimalsequences derived from the murine or other non-human immunoglobulin. Forthe most part, humanized antibodies are human immunoglobulins (recipientantibody) in which residues from a complementarity-determining region(CDR) of the recipient are replaced by residues from a CDR of theoriginal antibody (donor antibody) while maintaining the desiredspecificity, affinity, and capacity of the original antibody. In someinstances, Fv framework residues of the human immunoglobulin may bereplaced by corresponding non-human residues. Furthermore, humanizedantibodies can comprise residues that are not found in either therecipient antibody or in the imported CDR or framework sequences. Thesemodifications are made to further refine and optimize antibodyperformance. In general, the humanized antibody will comprisesubstantially all of at least one, and typically two, variable domains,in which all or substantially all of the CDR regions correspond to thoseof the original antibody and all or substantially all of the FR regionsare those of a human immunoglobulin consensus sequence. For furtherdetails see Jones et al. (1986) Nature 321: 522; Reichmann et al. (1988)Nature 332: 323; Verhoeyen et al. (1988) Science 239:1534 (1988); andPresta (1992) Curr. Op. Struct. Biol. 2:593, each of which is hereinincorporated by reference in its entirety.

The choice of human variable domains, both light and heavy, to be usedin making the humanized antibodies is very important to reduceantigenicity. According to the so-called “best-fit” method, the sequenceof the variable domain of an antibody of this invention is screenedagainst the entire library of known human variable-domain sequences. Thehuman sequence which is closest to that of the mouse is then accepted asthe human framework (FR) for the humanized antibody (Sims et al. (1993)J. Immun., 151:2296; Chothia and Lesk (1987) J. Mol. Biol. 196:901).Another method uses a particular framework from the consensus sequenceof all human antibodies of a particular subgroup of light or heavychains. The same framework can be used for several different humanizedantibodies (Carter et al. (1992) PNAS 89:4285; Presta et al. (1993) J.Immunol. 51:1993).

It is further important that antibodies be humanized while retainingtheir high affinity for KIR3DL2, and other favorable biologicalproperties. To achieve this goal, according to a preferred method,humanized antibodies are prepared by a process of analysis of theparental sequences and various conceptual humanized products usingthree-dimensional models of the parental and humanized sequences.Three-dimensional immunoglobulin models are commonly available and arefamiliar to those skilled in the art. Computer programs are availablewhich illustrate and display probable three-dimensional conformationalstructures of selected candidate immunoglobulin sequences. Inspection ofthese displays permits analysis of the likely role of the residues inthe functioning of the candidate immunoglobulin sequence, i.e., theanalysis of residues that influence the ability of the candidateimmunoglobulin to bind its antigen. In this way, FR residues can beselected and combined from the consensus and import sequences so thatthe desired antibody characteristic, such as increased affinity for thetarget antigen(s), is achieved. In general, the CDR residues aredirectly and most substantially involved in influencing antigen binding.

In one example, the invention provides human, chimeric or humanizedanti-KIR3DL2 antibodies having a half-life of at least 5, 6, 8, 9, 10,15 or 20 days, and which substantially bind human FcgammaRIIIa (CD16)(e.g. via their constant region). For example an antibody having aconstant region of the IgG1 type, or a F(ab′)2 fragment will typicallyhave CD16 binding. More preferably, the antibody is a human, chimeric orhumanized activating anti-KIR3DL2 antibody which competes with antibodychAZ158 for binding to human KIR3DL2. For the purpose of illustrationwith preferred antibodies suitable for use according to the methodsherein, a chAZ158 antibody can be used to prepare a humanized antibody.Preferred humanized antibodies according to the invention comprise ahuman framework, at least one CDR from a non-human antibody, and inwhich any constant region present is substantially identical to a humanimmunoglobulin constant region, e.g., at least about 60-90%, preferablyat least 95% identical. Hence, all parts of a humanized antibody, exceptpossibly the CDR's, are substantially identical to corresponding partsof one or more native human antibody sequences. In some instances, thehumanized antibody, in addition to CDRs from a non-human antibody, wouldinclude additional non-human residues in the human framework region.

The design of humanized antibodies can be carried out as follows. Whenan amino acid falls under the following categories, the framework aminoacid of a human antibody to be used (acceptor antibody) is replaced by aframework amino acid from a CDR-providing non-human antibody (donorantibody): (a) the amino acid in the human framework region of theacceptor antibody is unusual for human antibody at that position,whereas the corresponding amino acid in the donor antibody is typicalfor human antibody in that position; (b) the position of the amino acidis immediately adjacent to one of the CDR's; or (c) the amino acid iscapable of interacting with the CDR's in a tertiary structure antibodymodel (see, C. Queen et al. Proc. Natl. Acad. Sci. USA 86, 10029 (1989),and Co et al., Proc. Natl. Acad. Sci. USA 88, 2869 (1991), thedisclosures of which are incorporated herein by reference).

For further detailed description of the production of humanizedantibody, see Queen et al., op. cit. and Co et al., op. cit. and U.S.Pat. Nos. 5,585,089, 5,693,762, 5,693,761, and 5,530,101, thedisclosures of which are incorporated herein by reference. Usually, theCDR regions in humanized antibodies are substantially identical, andmore usually, identical to the corresponding CDR regions in the mouseantibody from which they were derived. Although not usually desirable,it is sometimes possible to make one or more conservative amino acidsubstitutions of CDR residues without appreciably affecting the bindingaffinity of the resulting humanized antibody. Occasionally,substitutions of CDR regions can enhance binding affinity. Other thanfor the specific amino acid substitutions discussed above, the frameworkregions of humanized antibodies are usually substantially identical, andmore usually, identical to the framework regions of the human antibodiesfrom which they were derived. Of course, many of the amino acids in theframework region make little or no direct contribution to thespecificity or affinity of an antibody. Thus, many individualconservative substitutions of framework residues can be toleratedwithout appreciable change of the specificity or affinity of theresulting humanized antibody. The antigen binding region of thehumanized antibody (the non-human portion) can be derived from anantibody of nonhuman origin, referred to as a donor antibody, havingspecificity for KIR3DL2. For example, a suitable antigen binding regioncan be derived from a chAZ158 monoclonal antibody. Other sources includeKIR3DL2-specific antibodies obtained from nonhuman sources, such asrodent (e.g., mouse and rat), rabbit, pig, goat or non-human primate(e.g., monkey) or camelid animals (e.g., camels and llamas).Additionally, other polyclonal or monoclonal antibodies, such asantibodies which bind to the same or similar epitope as a chAZ158antibody, can be made (e.g., Kohler et al., Nature, 256:495-497 (1975);Harlow et al., 1988, Antibodies: A Laboratory Manual (Cold SpringHarbor, N.Y.); and Current Protocols in Molecular Biology, Vol. 2(Supplement 27, Summer '94), Ausubel et al., Eds. (John Wiley & Sons:New York, N.Y.), Chapter 11 (1991)).

In one embodiment, the humanized antibody having binding specificity forhuman KIR3DL2 (optionally further binding KIR3DL1 and/or KIR3DS1)comprises at least one CDR of nonhuman origin. For example, a humanizedantibody having a binding specificity for human KIR3DL2 comprises aheavy chain and a light chain. The light chain can comprise a CDRderived from an antibody of nonhuman origin which binds KIR3DL2 and anFR derived from a light chain of human origin. For example, the lightchain can comprise CDR1, CDR2 and/or CDR3 which have the amino acidsequence similar or substantially the same as that of the respective CDRof a chAZ158 antibody such that the antibody specifically binds to thehuman KIR3DL2. The heavy chain can comprise a CDR derived from anantibody of nonhuman origin which binds KIR3DL2 and an FR derived from aheavy chain of human origin. For example, the heavy chain can compriseCDR1, CDR2 and CDR3 which have the amino acid sequence set forth belowor an amino acid similar or substantially the same as that of therespective CDR of the chAZ158 antibody such that the antibodyspecifically binds to the human KIR3DL2.

An embodiment of the invention is a humanized antibody whichspecifically binds to human KIR3DL2, wherein the antibody binds a commondeterminant also present on KIR3DL1 and/or KIR3DS1, and wherein theantibody comprises a humanized light chain comprising three light chainCDRs from a chAZ158 antibody and a light chain variable region frameworksequence from a human antibody light chain. The invention furthercomprises a humanized heavy chain that comprises three heavy chain CDRsfrom a chAZ158 antibody and a heavy chain variable region frameworksequence from a human antibody heavy chain.

The portion of the humanized antibody or antibody chain which is ofhuman origin (the human portion) can be derived from any suitable humanantibody or antibody chain. For example, a human constant region orportion thereof, if present, can be derived from the kappa or lambdalight chains, and/or the gamma (e.g., gamma1, gamma2, gamma3, gamma4),μ, alpha (e.g., alpha1, alpha2), delta or epsilon heavy chains of humanantibodies, including allelic variants. A particular constant region,variants or portions thereof can be selected to tailor effectorfunction. The latter constant regions, or portions therefore can beselected to have increased or decreased binding to Fcgamma receptors(e.g., CD16 on NK cells). If present, human FRs are preferably derivedfrom a human antibody variable region having sequence similarity to theanalogous or equivalent region of the antigen binding region donor.Other sources of FRs for portions of human origin of a humanizedantibody include human variable consensus sequences (See, Kettleborough,C. A. et al., Protein Engineering 4:773-783 (1991); Queen et al., U.S.Pat. Nos. 5,585,089, 5,693,762 and 5,693,761, the teachings of all ofwhich are incorporated by reference herein in their entirety). Forexample, the sequence of the antibody or variable region used to obtainthe nonhuman portion can be compared to human sequences as described inKabat, E. A., et al., Sequences of Proteins of Immunological Interest,Fifth Edition, U.S. Department of Health and Human Services, U.S.Government Printing Office (1991). In a preferred embodiment, the FRs ofa humanized antibody chain are derived from a human variable regionhaving at least about 60% overall sequence identity, and preferably atleast about 80% overall sequence identity, with the variable region ofthe nonhuman donor (e.g., chAZ158 antibody).

Amino acids from the variable regions of the mature heavy and lightchains of antibodies are designated Hx and Lx respectively, where x is anumber designating the position of an amino acid according to the schemeof Kabat, Sequences of Proteins of Immunological Interest (NationalInstitutes of Health, Bethesda, Md., 1987 and 1991). Kabat lists manyamino acid sequences for antibodies for each subgroup, and lists themost commonly occurring amino acid for each residue position in thatsubgroup. Kabat uses a method for assigning a residue number to eachamino acid in a listed sequence, and this method for assigning residuenumbers has become standard in the field. Kabat's scheme is extendibleto other antibodies not included in his compendium by aligning theantibody in question with one of the consensus sequences in Kabat. Theuse of the Kabat numbering system readily identifies amino acids atequivalent positions in different antibodies. For example, an amino acidat the L50 position of a human antibody occupies the equivalent positionto an amino acid at position L50 of a mouse antibody. From N-terminal toC-terminal, both light and heavy chain variable regions comprisealternating framework and CDRs: FR1, CDR1, FR2, CDR2, FR3, CDR3 and FR4.The assignment of amino acids to each region is in accordance with thedefinitions of Kabat (1987) and (1991), supra and/or Chothia & Lesk, J.Mol. Biol. 196:901-917 (1987); Chothia et al., Nature 342:878-883(1989).

Binding and/or adhesion assays or other suitable methods can also beused in procedures for the identification and/or isolation of humanizedantibodies (e.g., from a library) with the requisite specificity(competition assays for example).

The antibody portions of nonhuman and human origin for use in theinvention include light chains, heavy chains and portions of light andheavy chains. These antibody portions can be obtained or derived fromantibodies (e.g., by de novo synthesis of a portion), or nucleic acidsencoding an antibody or chain thereof having the desired property (e.g.,binds KIR3DL2, sequence similarity, for example with the chAZ158antibody) can be produced and expressed. Humanized antibodies comprisingthe desired portions (e.g., antigen-binding region, CDR, FR, C region)of human and nonhuman origin can be produced using synthetic and/orrecombinant nucleic acids to prepare genes (e.g., cDNA) encoding thedesired humanized chain. To prepare a portion of a chain, one or morestop codons can be introduced at the desired position. For example,nucleic acid sequences coding for newly designed humanized variableregions can be constructed using PCR mutagenesis methods to alterexisting DNA sequences (see, e.g., Kamman, M., et al., Nucl. Acids Res.17:5404 (1989)). PCR primers coding for the new CDRs can be hybridizedto a DNA template of a previously humanized variable region which isbased on the same, or a very similar, human variable region (Sato, K.,et al., Cancer Research 53:851-856 (1993)). If a similar DNA sequence isnot available for use as a template, a nucleic acid comprising asequence encoding a variable region sequence can be constructed fromsynthetic oligonucleotides (see, e.g., Kolbinger, F., ProteinEngineering 8:971-980 (1993)). A sequence encoding a signal peptide canalso be incorporated into the nucleic acid (e.g., on synthesis, uponinsertion into a vector). If the natural signal peptide sequence isunavailable, a signal peptide sequence from another antibody can be used(see, e.g., Kettleborough, C. A., Protein Engineering 4:773-783 (1991)).Using these methods, methods described herein or other suitable methods,variants can be readily produced. In one embodiment, cloned variableregions can be mutagenized, and sequences encoding variants with thedesired specificity can be selected (e.g., from a phage library; see,e.g., Krebber et al., U.S. Pat. No. 5,514,548; Hoogengoom et al., WO93/06213, published Apr. 1, 1993).

The invention also relates to isolated and/or recombinant (including,e.g., essentially pure) nucleic acids comprising sequences which encodea humanized antibody or humanized antibody light or heavy chain of thepresent invention.

Another method of making “humanized” monoclonal antibodies is to use aXenoMouse (Abgenix, Fremont, Calif.) as the mouse used for immunization.A XenoMouse is a murine host according to this invention that has hadits immunoglobulin genes replaced by functional human immunoglobulingenes. Thus, antibodies produced by this mouse or in hybridomas madefrom the B cells of this mouse are already humanized. The XenoMouse isdescribed in U.S. Pat. No. 6,162,963, which is herein incorporated inits entirety by reference. Human antibodies may also be producedaccording to various other techniques, such as by using, forimmunization, other transgenic animals that have been engineered toexpress a human antibody repertoire (Jakobovitz et al., Nature 362:255(1993), or by selection of antibody repertoires using phage displaymethods. Such techniques are known to the skilled person and can beimplemented starting from monoclonal antibodies as disclosed in thepresent application.

The antibodies of the present invention, preferably a chAZ158-likeantibody, may also be derivatized to “chimeric” antibodies(immunoglobulins) in which a portion of the heavy light chain isidentical with or homologous to corresponding sequences in the originalantibody, while the remainder of the chain(s) is identical with orhomologous to corresponding sequences in antibodies derived from anotherspecies or belonging to another antibody class or subclass, as well asfragments of such antibodies, so long as they exhibit the desiredbiological activity (Cabilly et al., supra; Morrison et al., Proc. Natl.Acad. Sci. U.S.A, pp. 6851 (1984)).

Other derivatives within the scope of this invention includefunctionalized antibodies, i.e., antibodies that are conjugated orcovalently bound to a toxin, such as ricin, diphtheria toxin, abrin andPseudomonas exotoxin; to a detectable moiety, such as a fluorescentmoiety, a radioisotope or an imaging agent; or to a solid support, suchas agarose beads or the like. Methods for conjugation or covalentbonding of these other agents to antibodies are well known in the art.

Conjugation to a toxin is useful for targeted killing cells displayingKIR3DL receptors on their cell surfaces, e.g. malignant T cells. Oncethe antibody of the invention binds to the cell surface of such cells,it is internalized and the toxin is released inside of the cell,selectively killing that cell.

Conjugation to a detectable moiety is useful, inter alia, when anantibody of the invention is used for diagnostic purposes. Such purposesinclude, but are not limited to, assaying biological samples, e.g., ablood sample or tissue biopsy, for the presence of KIR3DL-expressingcells, and detecting the presence, level, or activity ofKIR3DL-expressing cells in an individual. Such assay and detectionmethods are also alternate embodiments of the present invention. Suchmethods are useful, e.g., for diagnosing conditions caused by orassociated with an increase in KIR3DL-expressing cell activity ornumber. Labeled antibodies of the invention can also be used in FACSsorting to purify or isolate KIR3DL-expressing cells from a biologicalsample.

Conjugation of an antibody of this invention to a solid support isuseful as a tool for affinity purification of cells bearing a KIR3DL ontheir cell surface from a biological sample, such as a blood sample ormucosal tissue biopsy from an individual. This method of purification isanother alternate embodiment of the present invention, as is theresulting purified population of cells.

In an alternate embodiment, an antibody that binds an epitope of aKIR3DL2 polypeptide, wherein said antibody is capable of modulating Tcell activity, may be incorporated into liposomes (“immunoliposomes”),alone or together with another substance for targeted delivery to ananimal. Such other substances include, but are not limited to, nucleicacids for the delivery of genes for gene therapy or for the delivery ofantisense RNA, or siRNA for suppressing a gene in a T cell, or toxins ordrugs for the targeted killing of cells.

Structural Properties of Recombinant AZ158 Antibodies

In one preferred embodiment, the antibody of the invention is a chimericor humanized IgG antibody prepared using the variable domain sequences(e.g. the entire variable domain, a portion thereof, or part or all ofthe CDRs) of the chAZ158 antibody (or another antibody that binds to thesame epitope as chAZ158). Preferred antibodies of the invention are thebivalent monoclonal antibodies comprising the variable region or CDRs ofchAZ158 as produced, isolated, and structurally and functionallycharacterized and described herein. In one example the antibody is achimeric bivalent antibody derived from AZ158, comprising a heavy chainvariable region comprising SEQ ID NO 8 and a light chain variable regioncomprising SEQ ID NO 10 (chAZ158), described herein in the sectiontitled Examples; in another example, the antibody is the alternativebivalent chimeric antibody made of the (two) heavy chain(s) comprisingthe heavy chain variable region of chAZ158 fused to a human IgG1constant region and the (two) light chain(s) comprising the light chainvariable region of chAZ158 fused to a human IgL Kappa constant region.Full-length, variable, and CDR sequences of these antibodies are setforth in Table 1. Additional sequences include the AZ158 VH region DNA(SEQ ID NO 7), AZ158 VL region DNA (SEQ ID NO 9), Leader-VH-AZ158-HuIgG1DNA (SEQ ID NO 17) and Leader-VL-AZ158-HuIgL Kappa DNA (SEQ ID NO 19).

TABLE 1 SEQ ID Antibody portion NO: Sequence AZ158 VH region 8QVQLKESGPG LVAPSQSLSI TCTVSGFSLT SFGVHWVRQP amino acidPGKGLEWLGV IWAGGSTNYN SALMSRLSIS KDNSKSQVFLKMNSLQNDDT AMYYCARGNS NHYVSSFYYF DYWGQGTTLT VSS AZ158 VL region 10DIQMTQSPSS LSASLGGKVT ITCKASQDIN KYIAWYQHKP amino acidGKGPRLLIHY TSTLQPGIPS RFSGSGSGRD YSFSISNLEP EDITTYYCLQ YDNLWTFGGG TKLEIKAZ158 VH CDR1 11 GFSLTSFGVH amino acid AZ158 VH CDR2 12 VIWAGGSTNYNSALMSamino acid AZ158 VH CDR3 13 GNSNHYVSSFYYFDY amino acid AZ158 VL CDR1 14KASQDINKYIA amino acid AZ158 VL CDR2 15 YTSTLQP amino acid AZ158 VL CDR316 LQYDNLWT amino acid Leader-VH- 18MAVLVLFLCL VAFPSCVLSQ VQLKESGPGL VAPSQSLSIT AZ158-HuIgG1CTVSGFSLTS FGVHWVRQPP GKGLEWLGVI WAGGSTNYNS amino acidALMSRLSISK DNSKSQVFLK MNSLQNDDTA MYYCARGNSNHYVSSFYYFD YWGQGTTLTV SSASTKGPSV FPLAPSSKSTSGGTAALGCL VKDYFPEPVT VSWNSGALTS GVHTFPAVLQSSGLYSLSSV VTVPSSSLGT QTYICNVNHK PSNTKVDKKVEPKSCDKTHT CPPCPAPELL GGPSVFLFPP KPKDTLMISRTPEVTCVVVD VSHEDPEVKF NWYVDGVEVH NAKTKPREEQYNSTYRVVSV LTVLHQDWLN GKEYKCKVSN KALPAPIEKTISKAKGQPRE PQVYTLPPSR DELTKNQVSL TCLVKGFYPSDIAVEWESNG QPENNYKTTP PVLDSDGSFF LYSKLTVDKSRWQQGNVFSC SVMHEALHNH YTQKSLSLSP GK Leader-VL- 20MRPSIQFLGL LLFWLHGAQC DIQMTQSPSS LSASLGGKVT AZ158-HuIgLITCKASQDIN KYIAWYQHKP GKGPRLLIHY TSTLQPGIPS Kappa amino acidRFSGSGSGRD YSFSISNLEP EDITTYYCLQ YDNLWTFGGGTKLEIKRTVA APSVFIFPPS DEQLKSGTAS VVCLLNNFYPREAKVQWKVD NALQSGNSQE SVTEQDSKDS TYSLSSTLTLSKADYEKHKV YACEVTHQGL SSPVTKSFNR GEC

Accordingly, in one aspect, the invention provides an isolatedmonoclonal antibody, or antigen binding portion thereof, comprising: (a)a VH region comprising an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 8 and 11-13, and (b) a VL region comprising anamino acid sequence selected from the group consisting of SEQ ID NOs: 10and 14-16; wherein the antibody specifically binds a KIR3DL2polypeptide, preferably wherein the antibody specifically binds a commondeterminant on KIR3DL1, KIR3DL2 and KIR3DS1. Preferred heavy and lightchain combinations include: (a) a heavy chain comprising the amino acidsequence of SEQ ID NO: 8 and (b) a light chain comprising the amino acidsequence of SEQ ID NO: 10; (a) a heavy chain comprising the amino acidsequence of amino acid positions 20 to 472 of SEQ ID NO: 18 and (b) alight chain comprising the amino acid sequence of amino acid positions21 to 233 of SEQ ID NO: 20; (a) a heavy chain comprising the three CDRshaving amino acid sequences of SEQ ID NOS: 11-13, or at least 3, 4, 5,6, 7 or 8 contiguous amino acid residues thereof and (b) a light chaincomprising the three CDRs having amino acid sequences of SEQ ID NOS:14-16, or at least 3, 4, 5, 6, 7 or 8 contiguous amino acid residuesthereof.

In another aspect, the invention provides heavy chain and lightimmunoglobulin chains that comprise the CDR's, CDR2s and/or CDR3s of therespective heavy and light chains of chAZ158, or combinations thereof,and antibodies that comprise such heavy and/or light chains. The CDRregions are delineated using the Kabat system (Kabat et al. (1991)Sequences of Proteins of Immunological Interest, Fifth Edition, U.S.Department of Health and Human Services, NIH Publication No. 91-3242).The heavy chain CDRs of chAZ158 are located at amino acid positions 26to 35 (CDR1), positions 50 to 65 (CDR2) and positions 98 to 112 (CDR3)in SEQ ID NO: 8. The light chain CDRs of chAZ158 are located at aminoacid positions 24 to 34 (CDR1), positions 50 to 56, optionally 51 to 56,optionally 51 to 57 (CDR2) and positions 89 to 96 (CDR3) in SEQ ID NO:10. The respective CDRs are also provided in SEQ ID NOS 11-16. Alsoencompassed, for each of the heavy and light chains, are CDR sequencescomprising at least 3, 4, 5, 6, 7 or 8 contiguous amino acid residues ofany of the foregoing amino acid positions in the CDRs 1, 2 and 3. Alsoencompassed, for each of the heavy and light chains, are CDR sequenceshaving at least 50%, 60%, 70%, 80% or 90% sequence identity of any ofthe foregoing amino acid positions in the CDRs 1, 2 and 3. In oneaspect, the invention provides a humanized antibody heavy or light chaincomprising antigen-binding residues from the CDRs of antibody AZ158,e.g. the three CDRs for each of the heavy and light chains of AZ158, ina human acceptor framework, wherein each CDR comprises at least 3, 4, 5,6, 7 or 8 contiguous amino acid residues of the respective CDR's, CDR2sand/or CDR3s of the respective heavy or light chain of AZ158.Optionally, one, two, three or more amino acid residues of any one ormore of said CDRs are the same as those in the human acceptor sequence.

Accordingly, in another aspect, the invention provides an immunoglobulinheavy chain, or antigen binding portion thereof comprising: (a) a VHCDR1 comprising an amino acid sequence of SEQ ID NO: 11; (b) a VH CDR2comprising an amino acid sequence of SEQ ID NO: 12; and (c) a VH CDR3comprising an amino acid sequence of SEQ ID NO: 13. In another aspect,the invention provides an immunoglobulin light chain, or antigen bindingportion thereof comprising (a) a VL CDR1 comprising an amino acidsequence of SEQ ID NO: 14; (b) a VL CDR2 comprising an amino acidsequence of SEQ ID NO:15; and (c) a VL CDR3 comprising an amino acidsequence of SEQ ID NO: 16. Preferably said heavy chain comprises a heavychain variable region comprising VH CDR1, VH CDR2 and VH CDR3 fused to ahuman IgG chain constant region. Preferably said light chain variableregion comprising VL CDR1, VH CDR2 and VH CDR3 fused to a human kappachain constant region. Preferably said human IgG chain constant regionis an IgG1 isotope. Also provided is an antibody that is a tetramercomprising two of said heavy chains and two of said light chains.

In one aspect, the invention provides an isolated monoclonal antibody,or antigen binding portion thereof, comprising: (a) a VH regiondescribed herein (e.g. a variable region, portion thereof, or a variableregion comprising VH CDR1, CDR2 and/or CDR3 described herein) fused to ahuman IgG chain constant region, and (b) a VL region described herein(i.e. a variable region, portion thereof, or a variable regioncomprising VH CDR1, CDR2 and/or CDR3 described herein) fused to a humankappa chain constant region; wherein the antibody specifically binds aKIR3DL2 polypeptide.

In yet another embodiment, an antibody of the invention comprises heavyand light chain variable regions comprising amino acid sequences thatare homologous to the amino acid sequences of the preferred antibodiesdescribed herein, and wherein the antibodies retain the desiredfunctional properties of the anti-KIR3DL2 antibodies of the invention.Optionally, the VH domain comprises amino acid modifications of one ormore CDR residues, e.g. where the modifications essentially maintain orimprove affinity of the antibody. For example, the antibody variant mayhave one, two, three, or from one to about seven amino acidsubstitutions in the above VH or VL CDR sequences. For example, theinvention provides an isolated monoclonal antibody, or antigen bindingportion thereof, comprising a heavy chain variable region and a lightchain variable region, wherein: (a) the VH region comprises an aminoacid sequence that is at least 50%, 60%, 70%, 80% or 90% identical to anamino acid sequence selected from the group consisting of SEQ ID NOs: 8and 11-13; (b) the VL region comprises an amino acid sequence that is atleast 50%, 60%, 70%, 80% or 90% identical to an amino acid sequenceselected from the group consisting of SEQ ID NOs: 10 and 14-16; (c) theantibody specifically binds to a KIR3DL2 polypeptide and exhibits atleast one of the functional properties described herein, preferablyseveral of the functional properties described herein.

In other embodiments, the CDR, VH and/or VL, or constant region aminoacid sequences may be 50%, 60%, 70%, 80%, 85%, 90%, 95%, 96%, 97%, 98%or 99% identical to the sequences set forth above. An antibody havingCDR, VH and/or VL regions having high (i.e., 80% or greater) identity tothe CDR, VH and/or VL, or constant regions of the sequences set forthabove can be obtained by mutagenesis (e.g., site-directed orPCR-mediated mutagenesis) of nucleic acid molecules encoding the CDR, VHand/or VL of SEQ ID NOs: 6 to 16, followed by testing of the encodedaltered antibody for retained function (e.g., KIR3DL2 binding affinity,slowing proliferation of KIR3DL2-expressing cells, induction of ADCC).

The percent identity between two sequences is a function of the numberof identical positions shared by the sequences (i.e., % identity=# ofidentical positions/total # of positions×100), taking into account thenumber of gaps, and the length of each gap, which need to be introducedfor optimal alignment of the two sequences. The comparison of sequencesand determination of percent identity between two sequences can beaccomplished using a mathematical algorithm in a sequence analysissoftware. Protein analysis software matches similar sequences usingmeasures of similarity assigned to various substitutions, deletions andother modifications, including conservative amino acid substitutions.

The percent identity between two amino acid sequences can be determined,e.g., using the Needleman and Wunsch (J. Mol. Biol. 48:444-453 (1970))algorithm which has been incorporated into the GAP program in the GCGsoftware package (available at http://www.gcg.com), using either aBlossum 62 matrix or a PAM250 matrix, and a gap weight of 16, 14, 12,10, 8, 6, or 4 and a length weight of 1, 2, 3, 4, 5, or 6. Polypeptidesequences can also be compared using FASTA, applying default orrecommended parameters. A program in GCG Version 6.1, FASTA (e.g.,FASTA2 and FASTA3) provides alignments and percent sequence identity ofthe regions of the best overlap between the query and search sequences(Pearson, Methods Enzymol. 1990; 183:63-98; Pearson, Methods Mol. Biol.2000; 132:185-219). The percent identity between two amino acidsequences can also be determined using the algorithm of E. Meyers and W.Miller (Comput. Appl. Biosci., 1988; 11-17) which has been incorporatedinto the ALIGN program (version 2.0), using a PAM120 weight residuetable, a gap length penalty of 12 and a gap penalty of 4.

Another algorithm for comparing a sequence to other sequences containedin a database is the computer program BLAST, especially blastp, usingdefault parameters. See, e.g., Altschul et al., J. Mol. Biol. 1990;215:403-410; Altschul et al., Nucleic Acids Res. 1997; 25:3389-402(1997); each herein incorporated by reference. The protein sequences ofthe present invention can there be used as a “query sequence” to performa search against public databases to, for example, identify relatedsequences. Such searches can be performed using the XBLAST program(version 2.0) of Altschul, et al. 1990 (supra). BLAST protein searchescan be performed with the XBLAST program, score=50, wordlength=3 toobtain amino acid sequences homologous to the antibody molecules of theinvention. To obtain gapped alignments for comparison purposes, GappedBLAST can be utilized as described in Altschul et al., 1997 (supra).When utilizing BLAST and Gapped BLAST programs, the default parametersof the respective programs (e.g., XBLAST and NBLAST) can be used. Seehttp://www.ncbi.nlm.nih.gov.

In certain embodiments, an antibody of the invention comprises a VHregion comprising CDR1, CDR2 and CDR3 sequences and a VL regioncomprising CDR1, CDR2 and CDR3 sequences, wherein one or more of theseCDR or variable region sequences comprise specified amino acid sequencesbased on the preferred antibodies described herein (e.g. chAZ158 and anyof SEQ ID NOs 6-16), or conservative modifications thereof, and whereinthe antibodies retain the desired functional properties of theanti-KIR3DL2 antibodies of the invention. Conservative sequencemodifications can be any amino acid modifications that do notsignificantly affect or alter the binding characteristics of theantibody containing the amino acid sequence. Such conservativemodifications include amino acid substitutions, additions and deletions.Modifications can be introduced into an antibody of the invention bystandard techniques known in the art, such as site-directed mutagenesisand PCR-mediated mutagenesis. “Conservative” amino acid substitutionsare typically those in which an amino acid residue is replaced with anamino acid residue having a side chain with similar physicochemicalproperties. Families of amino acid residues having similar side chainshave been defined in the art. These families include amino acids withbasic side chains (e.g., lysine, arginine, histidine), acidic sidechains (e.g., aspartic acid, glutamic acid), uncharged polar side chains(e.g. glycine, asparagine, glutamine, serine, threonine, tyrosine,cysteine, tryptophan), nonpolar side chains (e.g., alanine, valine,leucine, isoleucine, proline, phenylalanine, methionine), beta-branchedside chains (e.g. threonine, valine, isoleucine) and aromatic sidechains (e.g., tyrosine, phenylalanine, tryptophan, histidine). Thus, oneor more amino acid residues within the CDR regions of an antibody of theinvention can be replaced with other amino acid residues from the sameside chain family and the altered antibody can be tested for retainedfunction (i.e., the functions set forth in (c), (d) and (e) above) usingthe functional assays described herein.

The nucleic acid sequences encoding the chAZ158 antibody heavy chain andlight chain variable regions are shown in SEQ ID NOS 7 and 9,respectively. In one embodiment the invention provides a bivalentmonoclonal antibody that comprises the variable heavy chain region ofAZ158 transcribed and translated from a nucleotide sequence comprisingSEQ ID NO 7 or a fragment thereof (e.g. a sequence encoding CDR1, CDR2and/or CDR3 of the chAZ158 VH region), and the variable light chainregion of chAZ158 transcribed and translated from a nucleotide sequencecomprising SEQ ID NO 9 or a fragment thereof (e.g. a sequence encodingCDR1, CDR2 and/or CDR3 of the chAZ158 VL region).

Hypofucosylated Constant Regions

In view of the ability of the anti-KIR3DL2 antibodies of the inventionto induce ADCC when produced in cells yielding hypofucosylatedantibodies, the antibodies of the invention can also be made withmodifications that increase their ability to bind Fc receptors. Typicalmodifications include modified human IgG1 constant regions comprising atleast one amino acid modification (e.g. substitutions, deletions,insertions), and/or altered types of glycosylation, e.g.,hypofucosylation. Such modifications can for example increase binding toFcγRIIIa on effector (e.g. NK) cells.

Certain altered glycosylation patterns in constant regions have beendemonstrated to increase Fc receptor binding ability of antibodies. Suchcarbohydrate modifications can be accomplished by, for example,expressing the antibody in a host cell with altered glycosylationmachinery. Cells with altered glycosylation machinery have beendescribed in the art and can be used as host cells in which to expressrecombinant antibodies of the invention to thereby produce an antibodywith altered glycosylation. See, for example, Shields, R. L. et al.(2002) J. Biol. Chem. 277:26733-26740; Umana et al. (1999) Nat. Biotech.17:176-1, as well as European Patent No: EP 1,176,195; PCT PublicationsWO 06/133148; WO 03/035835; WO 99/54342, each of which is incorporatedherein by reference in its entirety.

Generally, such antibodies with altered glycosylation are“glyco-optimized” such that the antibody has a particular N-glycanstructure that produces certain desirable properties, including but notlimited to enhanced ADCC and effector cell receptor binding activitywhen compared to non-modified antibodies or antibodies having anaturally occurring constant region and produced by murine myeloma NSOand Chinese Hamster Ovary (CHO) cells (Chu and Robinson, Current OpinionBiotechnol. 2001, 12: 180-7), HEK293T-expressed antibodies as producedherein in the Examples section, or other mammalian host cell linescommonly used to produce recombinant therapeutic antibodies.

Monoclonal antibodies produced in mammalian host cells contain anN-linked glycosylation site at Asn297 of each heavy chain. Glycans onantibodies are typically complex biantennary structures with very low orno bisecting N-acetylglucosamine (bisecting GlcNAc) and high levels ofcore fucosylation. Glycan termini contain very low or no terminal sialicacid and variable amounts of galactose. For a review of effects ofglycosylation on antibody function, see, e.g., Wright & Morrison, TrendBiotechnol. 15:26-31(1997). Considerable work shows that changes to thesugar composition of the antibody glycan structure can alter Fc effectorfunctions. The important carbohydrate structures contributing toantibody activity are believed to be the fucose residues attached viaalpha-1,6 linkage to the innermost N-acetylglucosamine (GlacNAc)residues of the Fc region N-linked oligosaccharides (Shields et al.,2002).

FcγR binding requires the presence of oligosaccharides covalentlyattached at the conserved Asn297 in the Fc region of human IgG1, IgG2 orIgG3 type. Non-fucosylated oligosaccharide structures have recently beenassociated with dramatically increased in vitro ADCC activity. “Asn297”according to the invention means amino acid asparagine located at aboutposition 297 in the Fc region; based on minor sequence variations ofantibodies, Asn297 can also be located some amino acids (usually notmore than +3 amino acids) upstream or downstream.

Historically, antibodies produced in CHO cells contain about 2 to 6% inthe population that are nonfucosylated. YB2/0 (rat myeloma) and Lecl3cell line (a lectin mutant of CHO line which has a deficient GDP-mannose4,6-dehydratase leading to the deficiency of GDP-fucose or GDP sugarintermediates that are the substrate of alpha6-fucosyltransferase) havebeen reported to produce antibodies with 78 to 98% non-fucosylatedspecies. In other examples, RNA interference (RNAi) or knock-outtechniques can be employed to engineer cells to either decrease the FUT8mRNA transcript levels or knock out gene expression entirely, and suchantibodies have been reported to contain up to 70% non-fucosylatedglycan.

The invention comprises an antibody binding to KIR3DL2 beingglycosylated with a sugar chain at Asn297, said antibody showingincreased binding affinity via its Fc portion to FcγRIII. In oneembodiment of the invention, an antibody will comprise a constant regioncomprising at least one amino acid alteration in the Fc region thatimproves antibody binding to FcγRIIIa and/or ADCC.

In one aspect, the antibodies of the invention are hypofucosylated intheir constant region. Such antibodies may comprise an amino acidalteration or may not comprise an amino acid alteration but be producedor treated under conditions so as to yield such hypofucosylation. In oneaspect, an antibody composition of the invention comprises a chimeric,human or humanized antibody described herein, wherein at least 20, 30,40, 50, 60, 75, 85, 90, 95% or substantially all of the antibody speciesin the composition have a constant region comprising a core carbohydratestructure (e.g. complex, hybrid and high mannose structures) which lacksfucose. In one embodiment, provided is an antibody composition which isfree of antibodies comprising a core carbohydrate structure havingfucose. The core carbohydrate will preferably be a sugar chain atAsn297.

In one embodiment, the invention comprises an antibody composition ofthe invention, e.g. a composition comprising antibodies which bind toKIR3DL2, are glycosylated with a sugar chain at Asn297, wherein theantibodies are partially fucosylated. Partially fucosylated antibodiesare characterized in that the proportion of anti-KIR3DL2 antibodies inthe composition that lack fucose within the sugar chain at Asn297 isbetween 20% and 90%, preferably between 20% and 80%, preferably between20% and 50%, 55%, 60%, 70% or 75%, between 35% and 50%, 55%, 60%, 70% or75%, or between 45% and 50%, 55%, 60%, 70% or 75%. Preferably theantibody is of human IgG1 or IgG3 type.

The sugar chain can further show any characteristics (e.g. presence andproportion of complex, hybrid and high mannose structures), includingthe characteristics of N-linked glycans attached to Asn297 of anantibody from a human cell, or of an antibody recombinantly expressed ina rodent cell, murine cell (e.g. CHO cell) or in an avian cell (e.g.EBx® cell).

In one embodiment, the antibody is expressed in a cell that is lackingin a fucosyltransferase enzyme such that the cell line produces proteinslacking fucose in their core carbohydrates. For example, the cell linesMs704, Ms705, and Ms709 lack the fucosyltransferase gene, FUT8 (alpha(1,6) fucosyltransferase), such that antibodies expressed in the Ms704,Ms705, and Ms709 cell lines lack fucose on their core carbohydrates.These cell lines were created by the targeted disruption of the FUT8gene in CHO/DG44 cells using two replacement vectors (see U.S. PatentPublication No. 20040110704 by Yamane et al. and Yamane-Ohnuki et al.(2004) Biotechnol Bioeng 87:614-22, the disclosures of which areincorporated herein by reference). Other examples have included use ofantisense suppression, double-stranded RNA (dsRNA) interference, hairpinRNA (hpRNA) interference or intron-containing hairpin RNA (ihpRNA)interference to functionally disrupt the FUT8 gene. In one embodiment,the antibody is expressed in a cell line with a functionally disruptedFUT8 gene, which encodes a fucosyl transferase, such that antibodiesexpressed in such a cell line exhibit hypofucosylation by reducing oreliminating the alpha 1,6 bond-related enzyme.

In one embodiment, the antibody is expressed in cell lines engineered toexpress glycoprotein-modifying glycosyl transferases (e.g.,beta(1,4)-N-acetylglucosaminyltransferase III (GnTHI)) such thatantibodies expressed in the engineered cell lines exhibit increasedbisecting GlcNac structures which results in increased ADCC activity ofthe antibodies (PCT Publication WO 99/54342 by Umana et al. and Umana etal. (1999) Nat. Biotech. 17:176-180, the disclosures of which areincorporated herein by reference).

In another embodiment, the antibody is expressed and the fucosylresidue(s) is cleaved using a fucosidase enzyme. For example, thefucosidase alpha-L-fucosidase removes fucosyl residues from antibodies(Tarentino, et al. (1975) Biochem. 14:5516-5523). In other examples, acell line producing an antibody can be treated with a glycosylationinhibitor; Zhou et al. Biotech. and Bioengin. 99: 652-665 (2008)described treatment of CHO cells with the alpha-mannosidase I inhibitor,kifunensine, resulting in the production of antibodies withnon-fucosylated oligomannose-type N-glucans.

In one embodiment, the antibody is expressed in a cell line whichnaturally has a low enzyme activity for adding fucosyl to theN-acetylglucosamine that binds to the Fc region of the antibody or doesnot have the enzyme activity, for example the rat myeloma cell lineYB2/0 (ATCC CRL 1662). Hypofucosylated glycans can also be produced incell lines of plant origin, e.g. WO 07/084926A2 (Biolex Inc.), WO08/006554 (Greenovation Biotech GMBH), the disclosures of which areincorporated herein by reference. Other examples of cell lines include avariant CHO cell line, Led 3 cells, with reduced ability to attachfucosyl to Asn(297)-linked carbohydrates, also resulting inhypofucosylation of antibodies expressed in that host cell (WO 03/035835(Presta et al.) and Shields, R. X. et al. (2002) J. Biol. Chem.277:26733-26740, the disclosures of which are incorporated herein byreference).

In another embodiment, the antibody is expressed in an avian cell,preferably a cell line which naturally yields antibodies with low fucosecontent, e.g., WO2008/142124 (Vivalis S A). As demonstrated herein, useof an avian embryonic derived stem cell line EBx® (e.g., EB66 or EB14)yields a large proportion of IgG1 antibodies having a common N-linkedbiantennary-type oligosaccharide structure that comprises long chainswith terminal GlcNac that are highly galactosylated. Approximately halfof the IgG1 antibody population contains the N-linked non-fucosylatedbiantennary-type oligosaccharide structure. The invention thusencompasses methods of producing antibodies, and antibodies producedusing such methods, where methods for producing the antibodies compriseexpressing the antibody in an avian embryonic derived stem cell EBx®,preferably chicken or duck embryonic derived stem cell (e.g., EBx®) andmore preferably chicken EB14 cells or duck EB24 and EB66 cells,genetically engineered to express recombinant anti-KIR3DL antibody.

Avian embryonic cell lines have been generated by several differentinvestigators. For example, U.S. Pat. No. 5,340,740 describes thedevelopment of avian embryonic stem cells by culturing avianblastodermal cells in the presence of a mouse fibroblast feeder layer.U.S. Pat. No. 5,656,479 and WO 93/23528 also describe an avian cellculture of undifferentiated avian cells expressing an embryonic stemcell phenotype. U.S. Pat. No. 6,114,168 and WO 96/12793 describe methodsfor producing avian embryonic stem cells on CEFs using particular media.U.S. Pat. No. 6,280,970 describes transformed avian embryonicfibroblasts that contain SV40 T Ag within their genome. US patentpublication no. 2001/0019840A1 describes culture media for producingavian ES cells and methods for producing proteins in ES cells culturedin such medium. WO 00/47717 describes the processes for developing avianembryonic germ cell lines by culturing avian primordial germ cells inculture medium containing particular growth factors and differentiationinhibitory factors. In certain embodiments, such cells include, forexample, EB1, EB2, EB3, EB4, EB5, and EB14 cells, obtainable fromVIVALIS SA (Nantes, France) and described in FR02/02945, WO 03/07661 andWO2008/129058. These cells were obtained from chick or duck embryos atvery early steps of embryogenesis and exhibit a stem cell phenotype. Thecells are not genetically modified in their native state and grow up tohigh cell density in suspension in an animal serum free cell culturemedium.

In a preferred embodiment, the avian cell of the present invention is achicken or duck cell. EBx® cells have been generated using a fullydocumented two-step process, described along with more general methodsfor obtaining and preparing avian cells for production of an antibody inU.S. patent application No. 61/032,786, filed Feb. 29, 2008 andInternational patent publication no. WO2008/142124, filed May 21, 2008,the disclosures of which are incorporated herein by reference.

Examples of chicken EBx® cell lines include suspension chicken celllines EB14 (see WO 03/076601 and WO05/007840) or EBv13. Examples of duckEBx® cell lines include EB24, EB26, or EB66. The term “avian”, “bird”,“ayes” or “ava” as used herein is intended to have the same meaning, andwill be used indistinctly. “Birds” refer to any species, subspecies orrace of organism of the taxonomic class “ava”. In a preferredembodiment, “birds” refer to any animal of the taxonomicorder:—“Anseriformes” (i.e., duck, goose, swan and allies). According toa more preferred embodiment, the bird is a duck, more preferably a Pekinor Moscovy duck. Therefore, the instant invention provides a process forobtaining continuous diploid duck cell lines derived from embryonic stemcells (ES), wherein said duck cell lines do not produce replicationcompetent endogenous retrovirus particles. Example of duck EBx® celllines of the invention are EB24, EB26, EB66 or subclones thereof, suchas EB24-12.

The process of establishment of continuous diploid avian cell lines,named EBx®, of the invention generally comprises two steps: a)isolation, culture and expansion of embryonic stem (ES) cells from birdsthat do not contain complete endogenous proviral sequences, or afragment thereof, susceptible to produce replication competentendogenous retroviral particles, more specifically EAV and/or ALV-Eproviral sequences or a fragment thereof, in a complete culture mediumcontaining all the factors allowing their growth and in the presence ofa feeder layer and supplemented with animal serum; optionally, saidcomplete culture medium may comprise additives, such as additional aminoacids (i.e. glutamine), sodium pyruvate, betamercaptoethanol, proteinhydrolyzate of non-animal origin (i.e. yeastolate, plant hydrolyzates);b) passage by modifying the culture medium so as to obtain a totalwithdrawal of said factors, said feeder layer and said serum, andoptionally said additives, and further obtaining adherent or suspensionavian cell lines, named EBx®, that do not produce replication-competentendogenous retrovirus particles, capable of proliferating over a longperiod of time, in a basal medium in the absence of exogenous growthfactors, feeder layer and animal serum. As will be appreciated by thoseskilled in the art, the selection of the appropriate vector, e. g.,plasmid, components for proper transcription, expression (promoter,control sequences and regulatory sequence), and isolation of proteinsproduced in cell expression systems is known and routinely determinedand practiced by those having skill in the art.

The EBx® cells are typically transfected with at least one expressionvector wherein said expression vector comprises at least in thefollowing order:

-   -   a first expression cassette comprising the following DNA        sequences in the following order: promoter sequence (e.g. CMV        promoter), intronic sequence, DNA sequence (preferably cDNA        sequence) encoding the heavy chain of an antibody or a fragment        thereof, polyadenylation sequence;    -   a second expression cassette comprising the following DNA        sequences in the following order: promoter sequence (e.g. CMV        promoter), intronic sequence, DNA sequence (preferably cDNA        sequence) encoding the light chain of the antibody or a fragment        thereof, polyadenylation sequence;    -   a third expression cassette comprising the following DNA        sequences in the following order: viral promoter, antibiotic        resistance gene, polyadenylation sequence (e.g. SV40 promoter,        neomycin resistance gene, polyadenylation sequence);    -   optionally, at least one chicken lysozyme 5′ MAR element as        described in WO02/074969 or a human MAR element as described in        WO 2005/040377. The culturing of said transfected EBx® cells can        be performed according to the cell culture techniques well-known        by the man skilled in the art.

The antibodies of the invention, when expressed in EBx cells, display acommon N-linked oligosaccharide structure of a biantennary type thatcomprises long chains with terminal GlcNac that are highlygalactosylated and non-fucosylated and which confer strong ADCC activityto antibodies. The proportion of non-fucosylated antibodies represent atleast 20%, more preferably at least 35%, and more preferably at least45%, 50% or 55% of the antibodies or higher. Therefore, the inventionprovides a recombinant polypeptide, produced by transfected EBx cellline, preferably EB14 or duck EB66 cell lines, wherein the recombinantpolypeptide is characterized as having approximately 20%, morepreferably approximately 35%, and even more preferably approximately 45%of non-fucosylated N-linked oligosaccharide structures. More precisely,the invention provides a recombinant monoclonal antibody that bindsKIR3DL according to any of the embodiments of the present disclosure,produced by a transfected EBx cell line, preferably a duck EB66 cellline, wherein said antibody is characterized as having approximately 45%or more of non-fucosylated N-linked oligosaccharide structures. Saidantibody can be characterized as having approximately 35% or more ofnon-fucosylated N-linked oligosaccharide structures G0, G1 and G2. Theinvention also relates to an antibody that binds KIR3DL or population ofsuch antibodies, produced in EBx® cells, preferably in duck EB66 cells,and having increased ADCC activity compared to the same antibodyproduced in hydridoma or wild-type CHO cell line, preferably CHOK1 andCHO-DG44. The anti-KIR3DL antibody population produced in EBx® cells canalso be characterized as comprising a large proportion of antibodieswherein the Fc regions carry a common N-linked fucosylatedoligosaccharide structure of a biantennary type that comprises longchains with terminal GlcNac that are galactosylated and a largeproportion of antibodies wherein the Fc regions carry a common N-linkednon-fucosylated oligosaccharide structure of a biantennary type thatcomprises long chains with terminal GlcNac that are galactosylated. Theantibody population is characterized by having approximately 45% ofnon-fucosylated N-linked oligosaccharide structures. Most of theseantibodies, that is to say, more than 60%, 75%, 85%, or 95% of theseantibodies of the antibody population produced in EBx cells do notcontain sialic acid residues on the N-linked oligosaccharide structureof a biantennary type that is linked to the Fc region. A largeproportion of sialic acid residues are N-acetyl-neuraminic acid(NeuAC)—typically more than 80%, 90%, or 95% of sialic acid residues areNeuAc which are known to be non-immunogenic in humans. The remainingsmall proportion of sialic acid residues is composed ofN-glycolylneuraminic acid (NeuGc).

While antibodies in underivatized or unmodified form are preferred,particularly of the IgG1 or IgG3 type, or underivatized antibodiescomprising a modification in the constant region to improve antibodybinding to FcγRIIIa and/or ADCC, it is also possible to preparederivatized antibodies to make them cytotoxic. When bivalent IgG formsof such derivatized antibodies are used, they can thus target tumorcells in two distinct ways: by ADCC (e.g. when the antibodies bind Fcreceptors, for example via their constant regions) and by killing thecell via the cytotoxic moiety. In one embodiment, once the antibodiesare isolated and rendered suitable for use in humans, they arederivatized to make them toxic to cells. In this way, administration ofthe antibody to e.g. CTCL patients will lead to the relatively specificbinding of the antibody to KIR3DL2 polypeptide-expressing cancer cells,thereby providing an additional means for directly killing or inhibitingthe cells.

Purifying KIR3D Positive Cells Using the Antibodies of the Invention

In certain embodiments, the present antibodies are used to purify KIR3Dpositive cells from a biological sample. Biological samples can beobtained from a patient, e.g. for diagnostic or ex vivo therapeuticpurposes, or from individuals or non-human primates to obtain a sourceof such cells for research purposes.

KIR3D positive cells can be purified using the present antibodies withany of a number of standard methods. For example, peripheral blood cellscan be sorted using a FACS scanner using labeled antibodies specific forKIR3DL2, and optionally to other cell surface molecules typicallypresent on cells, e.g., CD4 for T cells; CD4 CD2+, CD3+, CD5+, CD8−,CD28+, CD45RO+ and/or TCRαβ+ for malignant cells in Sézary Syndrome;CD4+ and CD28− in inflammatory, autoimmune or cardiovascular diseases.

In addition, the antibodies of the invention can be conjugated orcovalently linked to a solid support and used to purify KIR3D positivecells or any cells expressing KIR3D from a biological sample, e.g., froma blood sample or mucosal tissue biopsy from a patient or otherindividual. Specifically, the biological sample is placed into contactwith the antibodies under conditions that allow cells within the sampleto bind to the antibody, and then the cells are eluted from thesolid-support-bound antibody.

Regardless of the method used to isolate or purify the KIR3D positivecells, the ability to do so is useful for numerous purposes, e.g. todiagnose a disorder characterized by a pathogenic expansion ofKIR3D-expressing cells, by assessing the number or activity or othercharacteristics of KIR3D positive cells obtained from a patient, or toevaluate the ability of the antibodies of the invention, or fragments orderivatives thereof, to modulate the activity or behavior of the cellsof a patient prior, e.g., to one of the herein-described treatmentsusing the antibodies. Further, purified KIR3D positive cells are usefulin a research context, e.g., to better characterize the cells and theirvarious properties and behaviors, as well as to identify compounds ormethods that can be used to modulate their behavior, activity, orproliferation. The antibodies of the invention can also be useful indiagnostic methods, for example in methods of detecting KIR polypeptideson cells, e.g., disease cells from a patient. The antibodies that bindall KIR3D polypeptides (KIR3DL1, DL2 and DS1) provide a method to detectall expressed KIR3D polypeptides with a single antibody, and furthermoreto distinguish KIR3D from KIR2D polypeptides. The KIR3D antibodies canoptionally be used in combination with KIR2D antibodies where the entirerange of KIR polypeptides is to be assessed.

Treatment of Disease

The present invention also provides pharmaceutical compositions thatcomprise an antibody according to the invention which specifically bindsto KIR3DL2 polypeptides on the surface of cells, and inhibits the growthor activity of the cells and/or leads to the elimination, preferably viaADCC, of the KIR3DL positive cells. The composition further comprises apharmaceutically acceptable carrier.

The invention further provides a method of inhibiting the growth oractivity of, and/or depleting, KIR3DL-positive cells, particularlyKIR3DL2-positive cells, in a patient in need thereof, comprising thestep of administering to said patient a composition according to theinvention. Such treatment methods can be used for a number of disorders,including but not limited to CTCL, SS and MF, inflammatory, autoimmuneand cardiovascular disorders.

In some embodiments, prior to the administration of the anti-KIR3DL2antibody or composition, the presence of KIR3DL (e.g. KIR3DL2) on cellsof the patient will be assessed, e.g., to determine the relative leveland activity of KIR3DL-positive cells in the patient as well as toconfirm the binding efficacy of the antibodies to the cells of thepatient. This can be accomplished by obtaining a sample of PBLs or cellsfrom the site of the disorder, and testing, e.g., using immunoassays, todetermine the relative prominence of markers such as CD4, etc., as wellas e.g. KIR3DL2 on the cells.

In one embodiment, where it is sought to inhibit the activity or growthof, or deplete, a patient's KIR3DL-positive cells, the ability of theanti-KIR3DL2 antibody to inhibit proliferation of or deplete a patient'sKIR3DL-positive cells is assessed. If the KIR3DL-positive cells areinhibited and/or depleted by the anti-KIR3DL2 antibody or composition,the patient is determined to be responsive to therapy with ananti-KIR3DL2 antibody or composition, and optionally the patient istreated with an anti-KIR3DL2 antibody or composition.

In other embodiments, the method may comprise the additional step ofadministering to said patient an appropriate additional therapeuticagent selected from an immunomodulatory agent, an immunosuppressiveagent, a hormonal agent, a chemotherapeutic agent, and a second antibodythat binds to a KIR3DL2 polypeptide. Such additional agents can beadministered to said patient as a single dosage form together with saidantibody, or as a separate dosage form. The dosage of the antibody (orantibody and the dosage of the additional therapeutic agentcollectively) are sufficient to detectably induce, promote, and/orenhance a therapeutic response in the patient. Where administeredseparately, the antibody, fragment, or derivative and the additionaltherapeutic agent are desirably administered under conditions (e.g.,with respect to timing, number of doses, etc.) that result in adetectable combined therapeutic benefit to the patient.

Mycosis fungoides and the more aggressive Sézary syndrome represent themost common forms of CTCL. The clinical course of MF/SS is usuallyindolent, with pruritic erythematous areas slowly developing over longperiods. Eventually, however, the erythematous patches becomeprogressively infiltrated, developing into plaques and finally toulcerating tumors. The prognosis of MF/SS is based on the extent ofdisease at presentation. Patients with stage I disease have a mediansurvival of 20 years or more, in comparison with a median survival ofapproximately 3 to 4 years for patients with stage III/IV disease.

The compositions of the invention can be used for treatment incombination with any agent known to be useful in the treatment of theparticular T cell malignancy. Although there is no current standard ofcare for MF/SS, there is a general tendency to rely on topicalinterventions for early disease delaying systemic and more toxic therapyuntil the development of extensive symptoms. Psoralen and ultraviolet Aradiation (PUVA), combined or not with low doses of interferon-α, iseffective in early-stage MF/SS, inducing complete remission (CR) in mostpatients. Local radiotherapy or total-skin electron-beam irradiation(TSEB) has been used with success to control advanced skin disease.Extracorporeal photopheresis may also be used successfully but is notgenerally available. Once the disease becomes refractory to topicaltherapy, interferon-α, the rexinoid bexarotene (Targretin®, LigandPharmaceuticals, San Diego, Calif.), a synthetic retinoid analogtargeting the retinoid X receptor, single-agent chemotherapy orcombination chemotherapy may be given. The duration of response ishowever often less than 1 year, and ultimately all patients haverelapses and the disease becomes refractory. The recombinantIL2-diphtheria toxin denileukin diftitox (DAB389IL-2, ONTAK®, LigandPharmaceuticals, San Diego, Calif.) is active in patients with stage Ibto stage IV CTCL refractory to previous treatments (overall objectiveresponse in 30% of 71 patients with a median duration response of 7months) and appears to have a beneficial effect on symptom relief andquality of life. More recently, denileukin diftitox has been tested in aPhase I trial in combination with bexarotene, since it induces CD25 upregulation in vitro. The combination was well tolerated and inducedobjective response in 67% of 14 patients. The most significant adverseevents were those already reported with bexarotene alone(hypertriglyceridemia and suppression of thyroid function due todecreased TSH production) and grade 3 or 4 lymphopenia but resolvingwithin one month of cessation of therapy. The time to treatment failurewas not reported in this study. In other studies, a chimeric monoclonalanti-CD4 (cM-T412, Centocor, Malvern, Pa.) was administered to 8patients with MF and induced objective response in 7 of them but with amedian response duration of only 5 months. Uvadex® (methoxsalen,Therakos Inc., Exton, Pa.) in extracorporeal photopheresis has alsoshown signs of efficacy. The humanized monoclonal antibody alemtuzumab(hu-IgG₁ anti-CD52 mAb, Campath®, Millennium Pharmaceuticals, Inc. andILEX Oncology, Inc., marketed and distributed in the US by BerlexLaboratories, Inc., Montville, N.J.) is indicated for the treatment ofB-cell chronic lymphocytic leukemia (B-CLL) in patients who have beentreated with alkylating agents and who have failed fludarabine therapy.It has been tested in patients with advanced MF/SS (stage III or IVdisease) and led to objective responses in at least half of cases (55%of 22 patients). Its side effect profile consists mainly ofimmunosuppression and infusion reactions. An independent retrospectivestudy also described significant cardiac toxicity in 4 out of 8patients. With long lasting remissions observed (median time totreatment failure 12 months, range 5 to 32+ months), alemtuzumab therapyappears to be the treatment with the more favorable median responseduration compared to all treatments reported to date. Each of thesetreatments can be used in combination with the antibodies of theinvention.

The antibodies produced using the present methods are particularlyeffective at treating autoimmune and inflammatory disorders, as well ascardiovascular disorders, most particularly acute coronary syndrome,arthritis, rheumatoid arthritis, rheumatoid vascularitis, systemic lupuserythematosus, multiple sclerosis, Wegener's granulomatosis, andspondylarthritis. In general, the present methods can be used to treatany disorder caused at least in part by the presence or activity ofKIR3DL-expressing cells, e.g., T cells such as CD4⁺CD28⁻ cellsexpressing KIR3DL2, and which can therefore be effectively treated byselectively killing or inhibiting the proliferation or activation ofKIR3DL2-expressing cells, e.g., by activating KIR3DL2 so as to transmitan inhibitory intracellular signal.

In some embodiments, prior to the administration of the anti-KIR3DL2antibody, the expression of KIR3DL on cells underlying the particulardisorder will be assessed. This can be accomplished by obtaining asample of PBLs or cells from the site of the disorder (e.g., from thesynovium in RA patients), and testing, e.g., using immunoassays, todetermine the relative prominence of markers such as CD4, CD28, etc., aswell as KIR3DL on the cells. Other methods can also be used to detectexpression of KIR3DL and other genes, such as RNA-based methods, e.g.,RT-PCR or Northern blotting.

The treatment may involve multiple rounds of antibody or compoundadministration. For example, following an initial round ofadministration, the level and/or activity of KIR3DL-expressing T cells,e.g., CD4⁺CD28⁻ T cells, malignant CD4+ T cells, in the patient willgenerally be re-measured, and, if still elevated, an additional round ofadministration can be performed. In this way, multiple rounds ofreceptor detection and antibody or compound administration can beperformed, e.g., until the disorder is brought under control.

The anti-KIR3DL2 antibodies of the invention can be used for treatmentin combination with any agent known to be useful in the treatment of theparticular inflammatory disorder, autoimmune disorder, or cardiovasculardisorder. In view of the anti-KIR3DL2 antibodies' ability to inhibitcell proliferation in the absence of immune effector cells, it may beadvantageous to administer KIR3DL2 antibodies in combination with animmunosuppressive treatment. Anti-KIR3DL2 antibodies can be combined forexample with steroidal anti-inflammatory agents, non-steroidalanti-inflammatory agents, anti-metabolites and other agents used intreating cardiovascular, inflammatory or autoimmune diseases. In someembodiments, anti-inflammatory agents comprise steroidalanti-inflammatory agents, which include glucocorticosteroids andmineralocorticosteroids. These may be administered by any methodssuitable for treating the inflammatory disorders, including, amongothers, oral, intravenous, intramuscular, dermal, or nasal routes. Insome embodiments, the anti-inflammatory agents comprise non-steroidalanti-inflammatory agents. These agents generally act by inhibiting theaction of cyclooxygenase and lipoxygenase enzymes, or receptors formediators generated by these enzymes. The non-steroidalanti-inflammatory compounds include non-selective COX inhibitors,selective COX inhibitors, as well as FLAP antagonists and 5-lipoxygenaseantagonists. In some embodiments, the anti-inflammatory agents cancomprise anti-metabolites that affect proliferation of cells involved inthe immune response. Suitable anti-metabolites include folate analogs,such as methotrexate; inosine monophosphate dehydrogenase (IMPDH)inhibitors, such as mycophenolate mofetil; and azathiopurine. Compoundsof this group generally affect production of the substrates necessaryfor DNA replication, thereby inhibiting the proliferation of cellsinvolved or activated in response to an inflammatory reaction. In someembodiments, the anti-inflammatory agent is an agent that blocks theaction of TNF-alpha, the major cytokine implicated in inflammatorydisorders. In some embodiments, the anti-TNF is an antibody that blocksthe action of TNF-alpha. An exemplary anti-TNF antibody is infliximab(Remicade®). In other embodiments, the anti-TNF-alpha agent is areceptor construct that binds TNF-alpha and prevents its interactionwith TNF receptors present on cells, e.g. entanercept (Enbrel®). Inother embodiments, the anti-inflammatory agent is any other agent (e.g.an antibody agent) having immunosuppressive properties and useful in thetreatment of the disorder being treated with the KIR3D antibody of theinvention.

Pharmaceutical Compositions

Pharmaceutically acceptable carriers that may be used in thesecompositions include, but are not limited to, ion exchangers, alumina,aluminum stearate, lecithin, serum proteins, such as human serumalbumin, buffer substances such as phosphates, glycine, sorbic acid,potassium sorbate, partial glyceride mixtures of saturated vegetablefatty acids, water, salts or electrolytes, such as protamine sulfate,disodium hydrogen phosphate, potassium hydrogen phosphate, sodiumchloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinylpyrrolidone, cellulose-based substances, polyethylene glycol, sodiumcarboxymethylcellulose, polyacrylates, waxes,polyethylene-polyoxypropylene-block polymers, and wool fat.

The compositions of the present invention may be administered orally,parenterally, by inhalation spray, topically, rectally, nasally,buccally, vaginally or via an implanted reservoir. The used hereinincludes subcutaneous, intravenous, intramuscular, intra-articular,intra-synovial, intrasternal, intrathecal, intrahepatic, intralesionaland intracranial injection or infusion techniques.

Sterile injectable forms of the compositions of this invention may beaqueous or an oleaginous suspension. These suspensions may be formulatedaccording to techniques known in the art using suitable dispersing orwetting agents and suspending agents. The sterile injectable preparationmay also be a sterile injectable solution or suspension in a non-toxicparenterally acceptable diluent or solvent, for example as a solution in1,3-butanediol. Among the acceptable vehicles and solvents that may beemployed are water, Ringer's solution and isotonic sodium chloridesolution. In addition, sterile, fixed oils are conventionally employedas a solvent or suspending medium. For this purpose, any bland fixed oilmay be employed including synthetic mono- or diglycerides. Fatty acids,such as oleic acid and its glyceride derivatives are useful in thepreparation of injectables, as are natural pharmaceutically-acceptableoils, such as olive oil or castor oil, especially in theirpolyoxyethylated versions. These oil solutions or suspensions may alsocontain a long-chain alcohol diluent or dispersant, such ascarboxymethyl cellulose or similar dispersing agents that are commonlyused in the formulation of pharmaceutically acceptable dosage formsincluding emulsions and suspensions. Other commonly used surfactants,such as Tweens, Spans and other emulsifying agents or bioavailabilityenhancers which are commonly used in the manufacture of pharmaceuticallyacceptable solid, liquid, or other dosage forms may also be used for thepurposes of formulation.

Several monoclonal antibodies have been shown to be efficient inclinical situations, such as Rituxan Herceptin (Trastuzumab) or Xolair(Omalizumab), and similar administration regimens (i.e., formulationsand/or doses and/or administration protocols) may be used with theantibodies of this invention. Schedules and dosages for administrationof the antibody in the pharmaceutical compositions of the presentinvention can be determined in accordance with known methods for theseproducts, for example using the manufacturers' instructions. Forexample, an antibody present in a pharmaceutical composition of thisinvention can be supplied at a concentration of 10 mg/mL in either 100mg (10 mL) or 500 mg (50 mL) single-use vials. The product is formulatedfor IV administration in 9.0 mg/mL sodium chloride, 7.35 mg/mL sodiumcitrate dihydrate, 0.7 mg/mL polysorbate 80, and Sterile Water forInjection. The pH is adjusted to 6.5. An exemplary suitable dosage rangefor an antibody in a pharmaceutical composition of this invention may bebetween about 10 mg/m² and 500 mg/m². However, it will be appreciatedthat these schedules are exemplary and that an optimal schedule andregimen can be adapted taking into account the affinity and tolerabilityof the particular antibody in the pharmaceutical composition that mustbe determined in clinical trials.

Quantities and schedule of injection of an antibody in a pharmaceuticalcomposition of this invention that saturate KIR3DL2-expressing cells for24 hours, 48 hours, 72 hours, a week or a month will be determinedconsidering the affinity of the antibody and its pharmacokineticparameters.

According to another embodiment, the antibody compositions of thisinvention may further comprise another therapeutic agent, includingagents normally utilized for the particular therapeutic purpose forwhich the antibody is being administered. The additional therapeuticagent will normally be present in the composition in amounts typicallyused for that agent in a monotherapy for the particular disease orcondition being treated. Such therapeutic agents include, but are notlimited to, therapeutic agents used in the treatment of autoimmunedisorders, inflammatory disorders or T cell lymphomas, e.g. SS or MF.

Further aspects and advantages of this invention will be disclosed inthe following experimental section, which should be regarded asillustrative and not limiting the scope of this application.

EXAMPLES Example 1—Generation of AZ158

mAbs were generated by immunizing 5 week old Balb C mice with polyclonalIL-2 activated NK population. After different cell fusions, the mAbAZ158 was initially selected for binding subset of NK cell population indifferent donors and two colour immunofluorescence analysis ofpolyclonal NK-cell populations indicated that AZ158 mAb reacts with thesame cell subset stained by Z27 (anti-KIR3DL1/S1) and Q66 (anti-KIR3DL2,IgM, generated in the inventors' laboratory) mAbs. The reactivity ofAZ158 was further analyzed on NK cell populations and clones incombination with additional antibodies, including EB6 (anti-p58.2.p50.2,CD158a), GL183 (anti-p58.2150.2, CD158b), PAX180 (anti-p50.3) and FES172(anti-p50.3), as well as Z27 and Q66, and it was observed that AZ158reacted with the same cell subset stained by the anti-KIR3DL1 andanti-KIR3DL2 mAbs. Similar results were also observed using a panel ofNK cell clones expressing different HLA class I specific NK receptors.

Example 2—Binding to KIR3D Receptors

A. Binding to KIR3DS1 on PBMC

Binding of antibody AZ158 to human NK cells was assessed. PBMC (thawedand gated for CD3⁻CD56⁺ NK lymphocytes) were incubated with mAbs, washedand labeled with PE-GaM, SAV-PE or GAM-IgG M. Flow cytometry was carriedout on an XL/MCL cytometer (Beckman Coulter). Acquisition and analysisare performed with EXPO™ 32 v1.2 software (Beckman Coulter). Antibodiesused were AZ158 and Z27-PE (specific for KIR3DL1 and KIR3DS1), DX9-PE(specific for KIR3DL1 only) and Q66 (IgM specific for KIR3DL2 only), allpreviously generated in the inventors' laboratory. Including DX9 inaddition to Z27 and Q66 permits the contribution of KIR3DS1 to thebinding profile to be assessed. Staining patterns indicated thatslightly more than half of NK cell population was stained by includingAZ158. Based on staining patterns, antibody AZ158 appeared to stain eachof the subsets of NK cells stained by antibodies Z27, Q66 and DX9indicating that AZ158 binds each of KIR3DL1, KIR3DL2 and KIR3DS1.

Flow cytometry experiments were repeated for a number of individualhealthy donors, using different antibodies to discriminate between thedifferent KIR3D populations within T and NK cells. Antibodies Z27-PE(specific for KIR3DL1 and KIR3DS1; Beckman Coulter Corp., CA, productref. IM3292) and DX9-PE (specific for KIR3DL1 only; Miltenyi Biotec,Germany product ref 130-092-473), together with AZ158-PE. Results for arepresentative individual having a genotype that expressed each of thethree KIR3D receptors are shown in FIGS. 4 and 5. FIGS. 4A and 4B showthe staining patterns for PBMC gated on CD3⁻CD56⁺ (NK lymphocytes),incubated with mAbs PE-DX9, PE-Z27 and PE-AZ158, washed and labeled.FIG. 4A shows Z27 staining on the x-axis indicating cells that areKIR3DL1/DS1+ and DX9 staining on the y-axis indicating the KIR3DL1+ cellpopulation. FIG. 4B shows AZ158 staining on the x-axis indicating cellsthat are KIR3DL1/DL2/DS1+ and DX9 staining on the y-axis indicating theKIR3DL1+ cell population. Comparing FIGS. 4A and 4B one can see anadditional population in the lower right quadrant of Figure B thatcorresponds to the additional KIR3DL2 specificity of AZ158 compared toZ27. On NK cells in this individual, about 14% of NK cells were positivefor each of KIR3DL2 and KIR3DS1 while 20-22% of NK cells expressedKIR3DL1.

FIGS. 5A and 5B show the staining patterns for PBMC gated on CD3⁺ (Tlymphocytes), incubated with mAbs PE-DX9, PE-Z27 and PE-AZ158, washedand labeled. FIG. 5A shows Z27 staining on the x-axis indicating cellsthat are KIR3DL1/DS1+ and DX9 staining on the y-axis indicating theKIR3DL1+ cell population. FIG. 5B shows AZ158 staining on the x-axisindicating cells that are KIR3DL1/DL2/DS1+ and DX9 staining on they-axis indicating the KIR3DL1+ cell population. Comparing FIGS. 5A and5B one can see a minor additional population in the lower right quadrantof FIG. 5B that corresponds to the additional KIR3DL2 specificity ofAZ158 compared to Z27. On NK cells in this individual, about 2% of NKcells were positive for any of KIR3DS1, KIR3DL2 and KIR3DS1.

B. Binding to Immobilized KIR3DL1 and KIR3DL2 Proteins

The binding of chimeric AZ158 (“chAZ158”, see Example 3) to KIR3DL2 andKIR3DL1 recombinant proteins (R&D Systems) was analyzed by SurfacePlasmon Resonance (SPR) using a Biacore T100 apparatus. FIG. 6 shows thesensorgrams for the binding of chAZ158 to KIR3DL2 (black; upper line)and KIR3DL1 (grey; lower line) chips, superimposed, with resonance units(RU) on the y-axis and time (seconds) on the x-axis. Antibody wasinjected at a constant concentration of 12 μg/ml over the KIR3DL2 andKIR3DL1 flow-cells. Background signals were subtracted online byco-injecting onto the reference flow cell (dextran alone). Sensorgramsare representative of three independent experiments. The results showthat the chAZ158 binds to both KIR3DL1 and KIR3DL2. Additionally, thedissociation phase on the sensorgram indicates that chAZ158 may bind toKIR3DL1 with greater stability to KIR3DL1 and KIR3DL2.

C. chAZ158 Binding Domain on KIR3DL2

Cells and Reagents.

HEK293T/17 cells were cultured in DMEM (Gibco) supplemented with sodiumpyruvate (1 mM), penicillin (100 U/ml), streptomycin (100 μg/ml) and 10%heat inactivated FCS (PAN-Biotech). Lipofectamine 2000 reagent, Trizol,SuperScript II reverse Transcriptase, pcDNA3.1 vector and anti-V5-FITCantibodies were purchased from Invitrogen. Goat anti-Human (H+L)-PE waspurchased from Beckman Coulter (PNIM1626).

RNA Extraction and cDNA Preparation.

PBMC (5·10⁶ cells) from Homo Sapiens were re-suspended into 1 ml ofTrizol reagent. RNA extraction was performed by adding 200 μlchloroform. After centrifugation (15 min, 13,000 rpm), RNA wasprecipitated from aqueous phase with 500 μl isopropanol. Afterincubation (10 min, RT) and centrifugation (10 min, 13,000), RNA waswashed with 70% ethanol and re-centrifugated (5 min, 13,000 rpm).

RNA was re-suspended in H₂O Rnase free water. cDNA was obtained usingSuperScript II reverse Transcriptase using 2 μg of specific RNA andfollowing manufacturer instructions.

Cloning of KIR3DL2 Domain 0, Domain 1 and Domain 2

Human KIR3DL2 (accession number U30272) domain 0, domain 1 and domain 2sequences are shown in Table 2.

TABLE 2 SEQ Ig-like domain  ID of KIR3DL2 NO: Amino acid sequenceDomain 0 21 PLMGGQDKPF LSARPSTVVP RGGHVALQCH YRRGFNNFMLYKEDRSHVPI FHGRIFQESF IMGPVTPAHA GTYRCRGSRPHSLTGWSAPS NPLVIMVTGN HRKPSLLAHP GPLLKSG Domain 1 22TVILQCWSDV MFEHFFLHRE GISEDPSRLV GQIHDGVSKANFSIGPLMPV LAGTYRCYGS VPHSPYQLSA PSDPLDIVIT GLYEKPSLSA QPGPTVQAGEDomain 2 23 NVTLSCSSWS SYDIYHLSRE GEAHERRLRA VPKVNRTFQADFPLGPATHG GTYRCFGSFR ALPCVWSNSS DPLLVSVTGN PSSSWPSPTE PSSKSGICRH LH

Homo Sapiens KIR3DL2 (accession number U30272) domain 0, domain 1 anddomain 2 sequences were amplified by PCR reaction from cDNA using 5′ AAGCT AGC GGT AAG CCT ATC CCT AAC CCT CTC CTC GGT CTC GAT TCT ACG CTC ATGGGT GGT CAG GAC AAA C (SEQ ID NO 24) (forward) and 3′ AA GGA TCC CTC TCCTGA TTT CAG CAG GGT (SEQ ID NO 25) (reverse); 5′ AA GCT AGC GGT AAG CCTATC CCT AAC CCT CTC CTC GGT CTC GAT TCT ACG ACA GTC ATC CTG CAA TGT TGG(SEQ ID NO 26) (forward) and 3′ AA GGA TCC CTC TCC TGC CTG AAC CGT GGG(SEQ ID NO 27) (reverse); 5′ AA GCT AGC GGT AAG CCT ATC CCT AAC CCT CTCCTC GGT CTC GAT TCT ACG AAC GTG ACC TTG TCC TGT AGC (SEQ ID NO 28)(forward) and 3′ AA GGA TCC ATG CAG GTG TCT GCA GAT ACC (SEQ ID NO 29)(reverse) oligonucleotides respectively. After TA-cloning andsequencing, sequences were cloned into pcDNA3.1 vector between NheI andBamHI restriction sites. These constructs were inserted between the CD33peptide leader and the CD24 GPI anchor (CD24 GPI anchor DNA and aminoacid sequences are shown in SEQ ID NOS 30 and 31, respectively)synthesized by MWG Biotech (inserted between BamHI and HindIIIrestriction sites).

Transfection.

HEK-293T/17 cells were seeded 24 hours prior to transfection into 6-wellplates (5·10⁵ cells/well) in DMEM without antibiotics. Transfectionswere performed using 5 μg of the different pcDNA3.1/KIR3DL2 domain 0,pcDNA3.1/KIR3DL2 domain 1 or pcDNA3.1/KIR3DL2 domain 2 constructs usingLipofectamine 2000 according to manufacturer instructions. To ensure DNApurity for transfection, Maxi-prep endotoxin free kit from Qiagen wasused. The Lipofectamine/DNA ratio used was fixed at 2/1. Cells wereharvested 48 hours after transfection for flow cytometry experiments.

Flow Cytometry.

Cells were harvested and stained in PBS 1×/BSA 0.2%/EDTA 2 mM bufferduring 1 H at 4° C. using 5 μg/ml of chAZ158 antibody. After two washesin staining buffer, cells were stained for 30 min at 4° C. with anti-V5antibody FITC (0.1 μl per well) and goat anti-human (H+L)-PE antibodies(1/200). After two washes, stainings were acquired on a BD FACS Canto IIand analyzed using the FlowJo software.

Results.

In order to determine where the chAZ158 antibody binds on the KIR3DL2molecule, three constructs were created. They consist of the DNAencoding the extracellular domain 0, 1 or 2 of the KIR3DL2 molecule (SEQID NOS 21, 22 and 23, respectively) linked to DNA encoding the CD24-GPIanchor (SEQ ID NO 30) to allow cell surface expression. These constructsare all tagged with the V5 epitope for cell surface detection by flowcytometry.

All the three constructs were expressed at the HEK-293T/17 cell surface;V5 positive cells could be detected in all conditions, although moreexpression of KIR3DL2 domain 0 construct at the cell surface wasobserved compared with KIR3DL2 domain 1 and domain 2 constructs. Resultsare shown in FIGS. 7-10, with V5-FITC indicated on the y-axis andchAZ158-GAH-PE on the x-axis. Staining on untransfected cells are shownin FIG. 7. A strong positive signal is observed with the chAZ158antibody on HEK-293/17 cells transfected with the KIR3DL2 domain 0construct (FIG. 8). No binding of the chAZ158 antibody could be detectedon KIR3DL2 domain 1 (FIG. 9) or domain 2 (FIG. 10). Therefore, it can beconcluded from this flow cytometry experiment that the chAZ158 antibodybinds to the KIR3DL2 extracellular domain 0 but not to domains 1 and 2.

Example 3—Chimerization of AZ158 Heavy and Light Chain Variable Regions

Frozen cell pellets of mouse hybridoma line, AZ158, were thawed andprocessed using the RNeasy Midi Kit (Qiagen cat. No. 75142) to isolatetotal RNA. About 5 micrograms of AZ158 RNA was subjected to reversetranscription to produce AZ158 cDNA using the Amersham Biosciences 1ststrand synthesis kit (Amersham Biosciences, Cat. No. 27-9261-01).Immunoglobulin heavy chain variable region (VH) cDNA was amplified byPCR using 12 different IgH primers in combination with a constant regionprimer in order to determine which primer pair was the most suitable forPCR. Similarly, immunoglobulin kappa chain variable region (VK) wasamplified using multiple IgK primers in combination with a kappaconstant region primer.

Only a single set of primers gave an amplification product for the heavychain variable regions. The amplification products were ligatedseparately into pCR2.1®-TOPO Vectors® for transformation into E. coliTOP10 bacteria, amplification and sequencing (using the BigDye®Terminator v3.0 Cycle Sequencing Ready Reaction Kit (ABI)). The aminoacid sequence of the heavy chain variable region (AZ158 VH) is set forthin SEQ ID NO: 8.

For the light chain, three single amplification products were obtained,designated MKV2, MKV6 and MKV7, with the remaining primers yielding noproducts. The amino acid sequence of the light chain variable region(AZ158 VK) arising from MKV6 is set forth in SEQ ID NO: 10. MKV2 lightchain corresponded to a sterile kappa transcript originating from amyeloma cell fusion partner. As described further below, MKV7 lightchain was non-functional in antigen binding assays. The MKV2 product wasa sterile transcript common to most hybridomas.

Chimerization of the AZ158 VK products derived using MKV6 and MKV7involved introducing, via the appropriate primers and PCR, a Hind IIIrestriction site, a Kozak translation initiation site and the PC613 (forMKV6) kappa leader sequence selected for similarity from the Kabatdatabase at the 5′ end and a splice donor site and Bam HI restrictionsite at the 3′ end of the AZ158 VK DNA sequence. The resulting PCRproduct was cloned into a vector encoding the constant region of thehuman kappa light chain so as to encode a full-length chimeric lightchain containing the variable region of the AZ light chain.

Chimerization of AZ158 VH involved introducing, by PCR and theappropriate primers, a Hind III restriction site, a Kozak translationinitiation site and the H26 leader sequence at the 5′ end, and, at the3′ end, the human gamma1 C region 5′ fragment up to a natural Apa Irestriction site. The resulting PCR product was cloned into a vectorencoding the constant region of the human IgG1 heavy chain so as toencode a full-length chimeric IgG1 heavy chain containing the variableregion of the AZ158 heavy chain.

The resulting plasmids encoding: a) the chimeric heavy and b) one of thetwo kappa chains were electroporated together into COS 7 cells.Conditioned media from these cells contained the resulting chimerizedIgG1-kappa antibody, chAZ158, which was then protein A purified. Thepurified antibodies were tested for binding to KIR3DL2-expressing Cou-Lcells. The chAZ158 antibody including the MKV6-derived kappa chain boundCou-L cells. However the antibody including the MKV7-derived kappa chaindid not bind these cells and therefore this kappa chain was not derivedfrom the mouse anti-KIR3DL2 antibody.

AZ158 is unusual in that it produces multiple kappa transcripts, withapparently functional coding sequences. We therefore expressed twochimeric antibodies with the two different kappa leader and variableregion sequences. The good expression of the chimeric version of thesetwo kappa chains in association with the single chimeric heavy chain inCOS cells after three days of culture indicated that these kappa codingsequences are functional. However, only chAZ158 antibody including theMKV6 light chain bound KIR3DL2-expressing cells. The reason for thiscomplex situation may be due to expression failure due to the non-codingregion of the MKV7 transcript such that the 2^(nd) allele producing theMKV6 transcript was rearranged in the parental B cell line.Alternatively, the hybridoma may be a product of a 3-cell fusion, fromwhich the chromosomes bearing both the functionally rearranged lightchains were retained, but from which one of the rearranged heavy chainchromosomes was expelled.

Example 4—AZ Inhibits Tumor Growth In Vivo

AZ158 (murine IgG2b) was tested for inhibition of tumor growth in asyngeneic mouse model. Briefly, different B16 murine melanoma cell lineswere transfected with KIR3DL2, yielding clone A1+ having about 90% cellsAZ158+, clone A1− having about 20% cells AZ158+ and clone A3 havingabout 3% cells AZ158, as well as a mock transfected control.

C57B16 mice were then treated with A1+ cells and AZ158 in three seriesof experiments and the number of lung metastases was assessed at day 20as a measure of tumor progression. In a first experiment (FIG. 1), A1+cells were injected at 0.3 10⁶ cells/mouse IV “tail” 100 μl, to 12 weekold female mice, followed by AZ158 via intraocular injection. Micereceived either A1+ cells only on day 0 (6 mice) or A1+ on day 0, 250μg/mouse AZ158 on day −1, and 100 μg/mouse on days 1, 5 and 7) (8 mice).Results in FIG. 1 demonstrate that AZ158 decreased the number ofmetastases significantly. In a second experiment (FIG. 2), A1+ cellswere injected at 0.3 10⁶ cells/mouse IV “tail” 200 μl, to 12 week oldfemale mice, followed by AZ158 via intraocular injection. Mice receivedeither A1+ cells only on day 0 (20 mice) or A1+ on day 0, 250 μg/mouseAZ158 on day −1, and 100 μg/mouse on days 1, 5 and 7 (20 mice). Resultsin FIG. 2 again demonstrate that AZ158 decreased the number ofmetastases significantly. In a third experiment (FIG. 3), A1+ cells wereinjected at 0.3 10⁶ cells/mouse IV “tail” 200 μl, to 13 week old femalemice, followed by AZ158 via intraocular injection. Mice received eitherA1+ cells only on day 0 (10 mice) or A1+ on day 0, 250 μg/mouse AZ158 onday −1, and 100 μg/mouse on days 1, 5 and 7 (10 mice). Results in FIG. 3again demonstrate that AZ158 decreased the number of metastasessignificantly.

Example 5—chAZ158 Directly Inhibits Cell Proliferation in CD4+ Cou-LCells

To investigate the mode of action of antibody AZ158, the antibody wasassessed for its direct effect on Cou-L cells (Sézary Syndrome cells;KIR3DL2 positive) in a cell proliferation assay.

Cou-L cells were cultured in RPMI (Gibco) supplemented with sodiumpyruvate (1 mM), 100 IU/ml Pen/Strep), 2 mM L-glutamine, IL-2 (200 U/ml)and 10% heat inactivated AB serum into 24 well plates (Falcon, reference353047). Antibodies were incubated overnight in 1×PBS at 4° C. intowhite opaque 96 well plates (Falcon, reference 353296). The chAZ158antibody (human IgG1 produced in EB66 cells) was used at 20 or 100μg/ml. A chimeric isotypic control produced in the same conditions wasused at the same concentrations. Finally, anti-Class I antibody (W6.32clone, 100 μg/ml) was also used as another control. Cou-L cells(1,000/well) were seeded into the wells previously washed once with1×PBS. Proliferation was assessed after two, five and eight days usingthe CellTiter-Glo Luminescent Cell Viability Assay (Promega) accordingto the manufacturer's instruction. Luminescence was measured using aMithras LB940 (Berthold Technologies).

The results are shown in FIG. 11. Luminescence units are shown on they-axis; luminescence depends on the quantity of ATP present, which inturn is proportional to the number of metabolically active cells at thetime proliferation is assessed. ChAZ158 but not control antibodysignificantly inhibited Cou-L cell proliferation in vitro.

Example 6—Expression of chAZ158 in CHO and EB66 Cells

ChAZ158 was expressed in both CHO and EB66 cells. Chicken EB14 and duckEB66 cells were grown in serum free medium (Excell—from SAFCBiosciences) supplemented with 2.5 mM glutamine. CHO-K1 cells weretransfected in suspension using CHO PFM serum free medium (Gibco, BRL,Gaithersburg) supplemented with 8 mM glutamine. During the selectionphase, the CHO-K1 cells were cultured in DMEM DF12 (Gibco, BRL,Gaithersburg), supplemented with 5% FBS and Geneticin.

Immunoglobulin heavy chain variable region (VH) cDNA and immunoglobulinkappa chain variable region (VK) cDNA encoding the VH and VK amino acidsequence set forth in SEQ ID NO: 8 and SEQ ID NO: 10 were cloned intoexpression vectors pVVS620 (pEF1/HTLV) and pVVS623 (pRSV). The cDNAsequences encoding the full chimeric AZ158 heavy and light chains areshown in SEQ ID NOS 17 and 19, respectively, and corresponding aminoacid sequences in SEQ ID NOS 18 and 20. Expression vectors pVVS620(pEF1/HTLV) and pVVS623 (pRSV) were transfected in serum-free mediuminto EB14, EB66 and CHO-K1 cells by electroporation (Amaxa). Three dayspost-transfection, the selection agent (0.25 mg/ml of Geneticin for EB14cells, 0.15 mg/mL for EB66 cells and 0.5 mg/mL for CHO-K1) is added tothe cell culture medium. The Geneticin resistant clones were isolated,picked up and cultured in larger vessels (microplates, flasks, thenbioreactors).

An ELISA screening assay was performed on stably transfected clones todetect antibody expression level in supernatant. This assay employs thequantitative sandwich enzyme immunoassay technique. An anti IgG-Fcspecific antibody is pre-coated onto a 96-well plate. Standards, samplesand conjugates are added to the wells and any IgG present is sandwichedby the immobilized antibody and a second enzyme-linked monoclonalantibody specific for IgG-kappa. Following a wash to remove any unboundsubstances and/or antibody-enzyme reagent, a substrate solution is addedto the wells and coloration develops in proportion to the amount of IgGbound. Reaction is stopped and coloration intensity is measured (O.D.490 nm). A standard curve is constructed by plotting the mean absorbancefor each standard on the y-axis against the concentration on the x-axisand drawing a best fit curve through the points of the graph. Theconcentration of each unknown sample is determined by calculating theconcentration of the IgG corresponding to the mean absorbance from thestandard curve. For samples, the concentration determined from thestandard curve must be multiplied by the dilution factor.

Example 7—chAZ158 Produced in EB66 Cells Induces ADCC of Target Cells

Materials and Methods

Cells and reagents. Cou-L cells were cultured in RPMI (Gibco)supplemented with sodium pyruvate (1 mM), 100 IU/ml Pen/Strep), 2 mML-glutamine, IL-2 (200 U/ml) and 10% heat inactivated AB serum into 24well plates (Falcon, reference 353047). B221 cells were cultured inRPMI-1640 media supplemented with 10% heat inactivated FBS, 2 mML-glutamine, 100 IU/ml Pen/Strep, and 1 mM Sodium Pyruvate into a T75flask.

Flow cytometric assay for CD107 mobilization and IFN-γ production.Thawed human PBMC stimulated or not overnight with 100 UI/mL of IL-2were mixed with Cou-L cells (Sézary Syndrome patient PBMC kindlyprovided by A. Bensussan) or B221 cell lines at an effector/target ratioequal to 10, alone or in the presence of mouse AZ158, chAZ158 producedin CHO, chAZ158 produced in EB14 or chAZ158 produced in EBX (EB66) (usedat 25 μg/mL) or rituxan (25 μg/mL). Cells were then incubated for 4hours at 37° C. in the presence of FITC conjugated anti-CD107 mAbs(Becton Dickinson) and monensin (Sigma). After incubation, cells werewashed in PBS containing 2 mM EDTA to disrupt cell conjugates andstained for extracellular markers (PC5 conjugated anti-CD56 and PC7conjugated anti-CD3 purchased from Beckman Coulter). Cells were thenfixed and permeabilized using IntraPrep reagent (Beckman Coulter).Intracellular IFN-γ was revealed using PE conjugated anti-IFN-γpurchased from Becton Dickinson. Samples were then analysed on FACScanto(Becton Dickinson).

Chromium release assay. The cytolytic activity of human PBMC wasassessed in a classical 4-h ³¹Cr-release assay in 96 well plates V fromGreiner. Briefly, Cou-L cells were labeled with ⁵¹Cr (100 μCi (3.7MBq)/1×10⁶ cells), then mixed with PBMC stimulated or not overnight with10 UI/mL of IL-2 at an effector/target ratio equal to 50, in thepresence of chAZ158 produced in CHO, chAZ158 produced in EB14 or chAZ158produced in EBX (concentration ranging from 0 to 50 μg/mL). After briefcentrifugation and 4 hours of incubation at 37° C., 504 supernatant wereremoved, and the ⁵¹Cr release was measured with a TopCount NXT betadetector (PerkinElmer Life Sciences, Boston, Mass.). All experimentalgroups were analyzed in duplicate or triplicate, and the percentage ofspecific lysis was determined as follows: 100×(mean cpm experimentalrelease−mean cpm spontaneous release)/(mean cpm total release−mean cpmspontaneous release). Percentage of total release obtained by lysis oftarget cells with 2% Triton X100 (Sigma).

Results

Results are shown in FIGS. 12 to 16, demonstrating a remarkable increasein ADCC of Sézary Syndrome cells for chAZ158 produced in EB14 or EBX(EB66) cells, compared to the same antibody produced in CHO cells.

FIG. 12 shows chAZ158-induced IFN-γ production by human NK cells againstCou-L cell targets. Thawed PBMC were incubated OVN (overnight) with orwithout IL-2 (5 or 100 U/mL) then mixed with Cou-L or B221 cells (E/Tratio=10) alone or in the presence of 25 μg/mL of mentioned mAbs (i.e.mouse or chimeric AZ158 or Rituxan). After 4 h incubation in thepresence of anti-CD107, cells were stained with anti-CD3, anti-CD56 andanti-IFN-γ. Percentages of IFN-γ producing NK cells (defined asCD3⁻CD56⁺ lymphocytes) are shown. Results are representative of 2independent experiments, made with 2 different sets of PBMC. In eachcase, and independent of IL-2 pre-treatment, chAZ158 produced by EB14 orEBX cells showed a strong increase of IFN-γ producing NK cells comparedto chAZ158 produced by CHO.

FIG. 13 shows chAZ158-induced CD107 mobilization by human NK cellsagainst Cou-L cells. Thawed PBMC were incubated OVN with or without IL-2(5 or 100 U/mL) then mixed with Cou-L or B221 cells (E/T ratio=10) aloneor in the presence of 25 μg/mL of mentioned mAbs (i.e. mouse or chimericAZ158 or Rituxan). After 4 h incubation in the presence of anti-CD107,cells were stained with anti-CD3, anti-CD56 and anti-IFN-γ. Percentagesof CD107 positive NK cells (defined as CD3⁻CD56⁺ lymphocytes) are shown.Results are representative of 2 independent experiments, made with 2different sets of PBMC. In each case, and independent of IL-2pre-treatment, chAZ158 produced by EB14 or EBX cells showed a strongincrease in percentages of CD107 positive NK cells compared to chAZ158produced by CHO.

FIG. 14 shows chAZ158-induced specific lysis of Cou-L cells by human NKcells. Thawed PBMC were incubated OVN with or without IL-2 (10 U/mL)then mixed with radiolabeled Cou-L cells (E/T ratio=50) alone or in thepresence of increasing concentration (up to 50 μg/mL) of mentionedchimeric AZ158 mAbs. After 4 h incubation, chromium release was measuredin culture supernatant. Shown specific lysis percentages were calculatedas described in M&M. Results are representative of 2 independentexperiments. For each concentration of antibody, and independent of IL-2pre-treatment, chAZ158 produced by EB14 or EBX cells showed a strongincrease in percentages of specific lysis compared to chAZ158 producedby CHO.

FIG. 15 shows chAZ158-induced IFN-γ production by heterologous NK cellsagainst Sézary syndrome patient PBMC. Thawed PBMC were incubated OVNwith or without IL-2 (5 or 100 U/mL) then mixed with Sézary syndromepatient PBMC or Cou-L cells (E/T ratio=10) alone or in the presence of25 μg/mL of chimeric AZ158 produced in EBX. After 4 h incubation in thepresence of anti-CD107, cells were stained with anti-CD3, anti-CD56 andanti-IFN-γ. Percentages of IFN-γ producing NK cells (defined asCD3⁻CD56⁺ lymphocytes) are shown. Results are representative of 2independent experiments, made with 2 different sets of effector PBMC aswell as 2 different sets of target patient PBMC. For eacheffector-target set, and again independently of IL-2 pre-treatment,chAZ158 produced by EBX cells induced a strong increase in IFN-γproducing NK cells compared to NK cells in the absence of chAZ158.

FIG. 16 shows chAZ158-induced CD107 mobilization by heterologous NKcells against Sézary syndrome patient PBMC. Thawed PBMC were incubatedOVN with or without IL-2 (5 or 100 U/mL) then mixed with Sézary syndromepatient PBMC or Cou-L cells (E/T ratio=10) alone or in the presence of25 μg/mL of mentioned mAbs (i.e. mouse or chimeric AZ158 or Rituxan).After 4 h incubation in the presence of anti-CD107, cells were stainedwith anti-CD3, anti-CD56 and anti-IFN-γ. Percentages of CD107 positiveNK cells (defined as CD3⁻CD56⁺ lymphocytes) are shown. Results arerepresentative of 2 independent experiments, made with 2 different setsof effector PBMC as well as 2 different sets of target patient PBMC. Foreach effector-target set, and again independently of IL-2 pre-treatment,chAZ158 produced by EBX cells induced a strong increase in CD107positive NK cells compared to NK cells in the absence of chAZ158.

All methods described herein can be performed in any suitable orderunless otherwise indicated herein or otherwise clearly contradicted bycontext.

The use of any and all examples, or exemplary language (e.g., “such as”)provided herein is intended merely to better illuminate the inventionand does not impose a limitation on the scope of the invention unlessotherwise indicated. No language in the specification should beconstrued as indicating any element is essential to the practice of theinvention unless as much is explicitly stated.

The description herein of any aspect or embodiment of the inventionusing terms such as reference to an element or elements is intended toprovide support for a similar aspect or embodiment of the invention that“consists of,” “consists essentially of” or “substantially comprises”that particular element or elements, unless otherwise stated or clearlycontradicted by context (e. g., a composition described herein ascomprising a particular element should be understood as also describinga composition consisting of that element, unless otherwise stated orclearly contradicted by context).

All publications and patent applications cited in this specification areherein incorporated by reference in their entireties as if eachindividual publication or patent application were specifically andindividually indicated to be incorporated by reference.

This invention includes all modifications and equivalents of the subjectmatter recited in the aspects or claims presented herein to the maximumextent permitted by applicable law.

Although the foregoing invention has been described in some detail byway of illustration and example for purposes of clarity ofunderstanding, it will be readily apparent to one of ordinary skill inthe art in light of the teachings of this invention that certain changesand modifications may be made thereto without departing from the spiritor scope of the appended claims.

We claim:
 1. A method of modulating T cell activity in a patientsuffering from arthritis, rheumatoid arthritis, or spondylarthritiscomprising the step of administering to said patient a compositioncomprising a pharmaceutically acceptable carrier or excipient and anantibody that specifically binds to an epitope within the KIR3DL2 domain0 consisting of SEQ ID NO: 21, wherein said antibody inhibitsproliferation of KIR3DL-expressing human T lymphocytes and comprises aconstant region of human IgG isotype, wherein said antibody: (a)comprises an Fc region of an IgG isotype modified to decrease binding toFc receptors; and/or (b) does not substantially induce ADCC of aKIR3DL-expressing target cell.
 2. The method of claim 1, furthercomprising administering to the patient an immune system suppressor. 3.The method of claim 1, wherein said patient suffers from arthritis. 4.The method of claim 1, wherein said patient suffers from rheumatoidarthritis.
 5. The method of claim 1, wherein said patient suffers fromspondylarthritis.
 6. The method of claim 1, wherein said antibody doesnot substantially induce ADCC of a KIR3DL-expressing target cell.
 7. Themethod of claim 1, wherein said antibody comprises an Fc region of anIgG isotype modified to decrease binding to Fc receptors.